Resin material for gas separation base and process for producing the same

ABSTRACT

This invention relates to resin material for gas separation base containing a cardo polyimide structure in which the hydrogen atoms in the side-chain benzyl and/or allyl position are halogenated at a rate of modification by halogen of 0.1% or more or resin material for gas separation base containing polymer in which the hydrogen atoms in the side-chain benzyl and/or allyl position are halogenated at a rate of modification by halogen of 34% or more and, additionally, relates to polymer which serves as raw material for the aforementioned resin material for gas separation base containing a cardo polymer structure and a process for producing said polymer; said polymer not only excels in such properties as solvent solubility, ease of conversion to film by a wet process, thermal stability, and chemical stability but also performs well in gas permeability and the process of this invention makes it possible to produce gas separation base, particularly gas separation membrane, whose gas permeability and gas selectivity can be readily controlled.

This application is the national phase under 35 U.S.C. §371 of PCTInternational Application No. PCT/JP00/01751 which has an Internationalfiling date of Mar. 22, 2000, which designated the United States ofAmerica.

FIELD OF TECHNOLOGY

This invention relates to resin materials for gas separation base and aprocess for producing the same and, particularly to resin materials forgas separation base consisting of polymers in which hydrogen atoms inthe side-chain benzyl and/or allyl position are replaced by halogenatoms, resin materials for gas separation base consisting of cardopolymers in which hydrogen atoms in the side-chain benzyl and/or allylposition are replaced by specified functional groups, halogen- orfunctional group-modified polymers of a cardo polyimide structure inwhich hydrogen atoms in the side-chain benzyl and/or allyl position arereplaced by halogen atoms or functional groups, a process for producingthe aforementioned polymers, and gas separation membranes based on theaforementioned resin materials for gas separation base. Resin materialsof this invention are useful in a variety of areas such as recovery ofcarbon dioxide from exhaust gas, separation of methane/carbon dioxidefrom natural gas, dehumidification of gases, and manufacture of oxygenand nitrogen from air and are also applicable as functional resinmaterials to a variety of areas.

BACKGROUND TECHNOLOGY

In recent years, numerous attempts have been made to separate and purifya mixture of gases by means of resin or polymer materials, inparticular, polymer gas separation membranes. For example, an attempt isbeing made to prepare oxygen-enriched air by passing air through apolymer gas separation membrane thereby selectively permeating oxygenand utilize it in medical care, combustion system, and the like.

Gas separation membranes to be used in the aforementioned applicationsare required to exhibit excellent permeability and selectivity towardthe gas to be separated. Moreover, depending upon the environment inwhich they are used, there is also a demand for additional propertyrequirements such as stability, heat resistance, chemical resistance,and high strength. Moreover, another important requirement is ease oftheir processibility into hollow fibers that provide a configurationsuitable for highly efficient gas separation. A large number of polymerseparation membranes have been tested for a variety of gases to seewhether they satisfy the aforementioned requirements or not.

An indicator of gas permeability of a polymer membrane or permeabilitycoefficient is expressed by the product of solubility coefficient thatis an indicator of the solubility of gas in the polymer membrane anddiffusion coefficient that is an indicator of the diffusibility of gasin the polymer membrane. Moreover, separation factor that is anindicator of selectivity is expressed by the ratio of the permeabilityof the gas to be separated to that of the gas not to be separated.Therefore, in order to improve selectively the permeability of the gasto be separated relative to that of the gas not to be separated, itbecomes necessary to improve selectively the solubility coefficientand/or diffusion coefficient of the gas to be separated relative to thatof the gas not to be separated.

A means that is considered to be effective for selectively improving thesolubility coefficient is to provide the membrane with an affinity tothe gas to be separated and various studies are being made on polymerscontaining a structure (a functional group) exhibiting a physical orchemical affinity to the gas to be separated.

Regarding separation membranes for CO₂, for example, Japan Kokai TokkyoKoho Hei 08-332,362 (1996) utilizes an idea of the existence of anaffinity between CO₂ and ester and reports on a polyimide-type gasseparation membrane synthesized from a cardo monomer containing an estergroup. Although this gas separation membrane is capable of improving theseparation factor, it still leaves the permeability coefficient at a lowlevel.

Yoshikawa et al., holding an idea of the existence of an affinitybetween CO₂ and amine, report on polymers prepared from a monomercontaining a tertiary amino group in Chemistry Letters, p. 243 (1994).In this case, however, they face the same problem as in theaforementioned cardo monomer containing an ester group, that is, theseparation factor improves but the permeability coefficient remains low.

In the case of polymers that are synthesized from monomers containing afunctional group exhibiting an affinity to gas as described in theaforementioned examples, such monomers become difficult to polymerize ifthe functional group in the monomer is chemically reactive or spatiallybulky; monomers of this type are not suitable for the synthesis ofpolymers for gas separation membranes that require a high degree ofpolymerization.

On the other hand, separately from the aforementioned methods, studiesare being made on an approach that introduces a functional groupexhibiting an affinity to gas to polymers after formation of the polymerbackbone. In numerous examples reported, the starting materials for thistype of polymer reaction are polymers in which aromatic rings containingside chains are halogenated in the benzyl position, that is, polymerscontaining a halogenated carbon atom in the benzyl position as an activesite in the reaction. Halogenated polymers containing halogenated carbonatoms in the benzyl position are generally easy to synthesize and showgood storage stability. These halogenated polymers exhibit highreactivity with nucleophilic reagents and the reaction can be controlledwith ease.

Such being the case, Okamoto et al. have proposed in Chemistry Letters,p.613 (1996) and in the specification of Japan Kokai Tokkyo Koho Hei09-173,801 (1997) to subject aromatic polyimides containing methylgroups as substituents to bromination at the side chain, convert thebrominated polymers into film, treat the film with an amine to giveamine-modified polyimides, and use the resulting film as a gasseparation membrane. Regarding this gas separation membrane, however, itis essential that the gas to be separated accompanies water vapor andthe examples disclose only those membranes which are used in theconfiguration of film and none in the configuration of hollow fiber thatis suitable for a gas separation membrane. Moreover, there is thepossibility of the amino groups in the polyimide polymer in questionbeing oxidized in air, but no description is given on the durability ofthe polymer. What is more, aromatic polyimides show low solventsolubility in general and it is often the case that solvents useful forchemical modification such as bromination are limited. Therefore, areaction in a homogeneous system, that is, a reaction to be carried outwith the reactants dissolved in a solvent may be applicable to one kindof aromatic polyimide, but it is not necessarily applicable to anotherkind of aromatic polyimide. Rather, a reaction in a homogeneous systemis often difficult to apply to aromatic polyimides.

On the other hand, there is a thought that providing the polymerbackbone with planarity and rigidity is effective for selectivelyimproving the diffusion coefficient and studies have been made onpolymers containing a bulky structure in the polymer backbone. Forexample, Japan Tokkyo Koho Sho 55-41,802 (1980) describes polyimide-typegas separation membranes containing a rigid polyimide skeleton to whicha substituent is introduced and states that restriction of free rotationaround the polymer backbone is an effective means for enhancing the gaspermeability and gas selectivity of polymer gas separation membranes.

Aside from the applications as gas separation membranes, a number ofreports have been made on modification of polymer backbone in order toprovide polymers with a variety of functions.

For example, Ohkawara et al. reported in 1966 on the reaction ofchlorinated poly(chloromethylstyrene) (PCMS) with various nucleophilicreagents and Nishikubo et al. reported on exceptional acceleration ofthis reaction by adding to the reaction system a quaternary ammoniumsalt or the so-called phase-transfer catalyst. Reference should be madeto Tadaomi Nishikubo et al., Journal of the Chemical Society of Japan,35 (1973) and, for an overview, to Journal of the Organic SyntheticChemistry Association, 51 (2) (1933).

Cabasso et al. synthesized modified polyphenylene oxide (PPO) in 1974 bytreating poly[oxy(2,6-dimethyl-1,4-phenylene)] with bromine orN-bromo-succinimide (NBS) to build a bromobenzyl structure and treatingthe brominated polymer with a compound of trivalent phosphorus tointroduce a pentavalent phosphate group [J. Appl. Polym. Sci., 18,1969-1968 (1974); J. Appl. Polym. Sci., 23, 2967-2988 (1979)]. Thefollowing reports are known on reactions of this kind: C. Pugh and V.Percec, Macromolecules, 19, 65 (1986); J. Liske, E. Borsig, and I. Tack,Angewand. Makromol. Chemie, 211, 121 (1993); and M. Scoponi and C.Ghighone, Angewand. Makromol. Chemie, 252, 237-256 (1997).

Starting with polyaryletheretherketone (PEEK) containing side-chainmethyl groups, Wang and Roovers in 1993 brominated the side-chain methylgroups by bromine and then treated the brominated PEEK with a variety ofnucleophilic reagents to give PEEK containing functional groups [J.Polym. Sci., Part A, 32, 2413-2424 (1994); Macromolecules, 26, 5295-5302(1993)].

Regarding the processibility of membrane polymers, aromatic polyimideswith a rigid structure that is advantageous in respect to selectivity ingas separation generally show extremely poor solvent solubility and thechoice of solvents in which chemical modification such as brominationcan be carried out is very much limited. For example, polyimidesprepared by the reaction of 2,4,6-trimethyl-1,3-phenylenediamine (TrMPD)with 3,4,3′,4′-biphenyltetra-carboxylic acid dianhydride show poorsolvent solubility and a solvent useful for the polyimides in questionis practically limited to dichloromethane. Therefore, if an attempt ismade to carry out the substitution reaction of the brominated polyimideswith an amine in dichloromethane, the dichloromethane reacts with theamine, that is, the substitution with amine cannot be carried out indichloromethane as a solvent. Thus, it is difficult to carry out thesubstitution with amine in a homogeneous system, that is, in a solutionof the aforementioned brominated polyimides in dichloromethane.

Poor solvent solubility such as this places great restrictions on thepreparation of membranes, particularly on the preparation of asymmetrichollow fibers which provide a suitable configuration for gas separationmembranes. Generally, in the preparation of asymmetric hollow fibers,the polymers are dissolved in a solvent which dissolves the polymerswell and is miscible with water which does not dissolve the polymers,for example, N-methylpyrrolidone (NMP) and dimethylacetamide (DMAc), andthe polymer solution is brought into contact with water to transfer thesolvent from the polymer solution to water and form the membrane (toform the active layer for gas separation). As described above, nosolvent but dichloromethane can be used for ordinary aromaticpolyimides. As dichloromethane is not miscible with water, it is notpossible to prepare asymmetric hollow fibers from these aromaticpolyimides.

Moreover, in the case of poor solvent solubility such as above, it isconceivable to carry out the modification of aromatic polyimides with anamine by first molding a membrane in the intended configuation from thebrominated polyimides and then immersing the molded polymer in asolution of amine-water system to replace the bromine with the amine. Onapplication of this procedure, however, it is not easy for the aminemolecules to penetrate into the inside of the membrane and replace thebromine and the resulting amine-modified moldings are not uniformthroughout the surface and the inside and only moldings exibiting a lowrate of permeation are obtained sometimes in practice.

The present inventors have taken note of good stability, solventsolubility, and processibility of cardo polymers and conducted studieson them. Here, cardo polymers is a generic name of polymers in whichcyclic groups are directly linked to the backbone. Structurally, a bulkysubstituent containing a quaternary carbon atom exists at a right angleto polymer backbone in cardo polymers and this structure helps toexhibit high heat resistance, good solvent solubility, hightransparency, high refractive index, low birefringence, and high gaspermeability due to the following effects; (1) restriction of therotation of polymer backbone, (2) conformational regulation of thebackbone and side chains, (3) hindrance of intermolecular packing, and(4) increase in aromaticity due to the introduction of an aromaticsubstituent to the side chains.

Functional resin materials, particularly functional resin materials forgas separation, are designed by controlling the sorption and diffusionof gas by adjusting primarily the average and distribution of freevolume that is an interstice in polymer chain and the motion of polymerchain. The present inventors have selected cardo monomers containing abulky group as a constitutional element to enlarge the free volume andcontrol the motion of polymer chain, conducted studies on development ofsuch monomers and their conversion to polymers, confirmed thatbifunctional monomers prepared by adding phenol, aniline, xylidine, andthe like to a base compound containing a skeleton of fluorene serve thepurpose, and developed cardo polymers from these monomers.

Moreover, as a result of studies aimed at improving the performance ofcardo polymers, the present inventors have found that modifying cardopolymers by replacing hydrogen atoms in the side-chain benzyl or allylposition partly or wholly with functional groups which are considered tohave an affinity for the physical or chemical properties of the gas tobe separated, for example, halogen atoms and functional groups andderivatives thereof which can replace the halogen atoms, can furtherimprove the performance in permeability and selectivity of gasseparation membranes while fully utilizing properties such as solventsolubility attributable to a bulky structure characteristic of cardopolyimides, ease of wet forming of membranes, thermal stabilityattributable to a rigid structure, and chemical stability attributableto a skeleton mainly composed of condensed aromatic rings, have foundfurther that the permeability and selectivity can be controlled easilythereby providing gas separation membranes with desired separationperformance, and have completed this invention.

Further, the present inventors have found that polymers containinghalogenated regions in the side-chain benzyl position or in the internalallyl position generally exhibit excellent gas separation performance inpermeability and selectivity and completed this invention.

Still further, the present inventors have found that the aforementionedcardo polymers can be used as a variety of functional polymers bychanging the kind of substituents at the side chain and completed thisinvention.

DISCLOSURE OF THE INVENTION

Accordingly, this invention relates to resin materials for gasseparation base comprising polymers of a cardo structure whose hydrogenatoms in the side-chain benzyl and/or ally position are halogenated at arate of modification of 0.1% or more.

The polymers here are preferably polyimides and, furthermore, theypreferably contain a cardo polyimide structure represented by thefollowing general formula (1)

wherein X is a divalent residue of an organic group and at least partlya divalent residue of an organic group represented by the followingstructural formula (A)

and Y is a tetravalent residue of an organic group; in the structuralformula (A), at least one of R₁ to R₂₀ is a halogen-modified substituentrepresented by

—CZR₂₁R₂₂

(wherein Z is a halogen atom and R₂₁ and R₂₂ will be defined later) andthe remainder of R₁ to R₂₀ and R₂₁ and R₂₂ in the halogen-modifiedsubstituent are hydrogen, halogen, linear or branched or cyclicunsubstituted or substituted alkyl, alkenyl, alkynyl, or aryl, theaforementioned alkyl, alkenyl, alkynyl and aryl groups may contain onekind or two kinds or more of hetero atoms selected from nitrogen,oxygen, sulfur, phosphorus, and halogens and may be identical with ordifferent from on another, the aforementioned remainder of R₁ to R₂₀ andR₂₁ and R₂₂ may pairand join together directly or through another atomto form a saturated or unsaturated bond in a cyclic structure, any oneof R₁₁ to R₁₅ and any one of R₁₆ to R₂₀ are respectively bonded to thenitrogen atom in the imide skeleton, and any one of R₁ to R₅ and any oneof R₆ to R₁₀ join together directly or through another atom to form asaturated or unsaturated bond in a cyclic structure.

The structural formula (A) in the aforementioned general formula (1) ispreferably a divalent residue of an organic group containing a fluoreneskeleton represented by the following structural formula (B)

wherein R₁ to R₄ and R₇ to R₂₀ are as defined in the structural formula(A); more preferably, at least one substituent selected from R₁₁ to R₂₀is modified by halogen in the structural formula (B).

In the aforementioned halogen-modified cardo polymers, the rate ofmodification by halogen of hydrogen atoms in the side-chain benzyland/or ally position is preferably 20% or more from the standpoint ofmanifestation of good gas separation performance.

This invention also relates to resin materials for gas separation basecomprising polyimides of a cardo structure represented by the followinggeneral formula (1)

wherein X is a divalent residue of an organic group and at least partlya divalent residue of an organic group represented by the followingstructural formula (A)

and Y is a tetravalent residue of an organic group; in the structuralformula (A), at least one of R₁ to R₂₀ is a functional group-modifiedsubstituent represented by

—CFuR₂₁R₂₂, —CFu₂R₂₁ and/or —CFu₃

(wherein Fu is a functional group or a derivative thereof which canreplace a halogen atom in the benzyl and/or ally position), theremainder of R₁ to R₂₀ and R₂₁ and R₂₂ are hydrogen, halogen, linear orbranched or cyclic unsubstituted or substituted alkyl, alkenyl, alkynyl,or aryl, the aforementioned alkyl, alkenyl, alkynyl and aryl groups maycontain one kind or two kinds or more of hetero atoms selected fromnitrogen, oxygen, sulfur, phosphorus, and halogens and may be identicalwith or different from one another, the aforementioned remainder of R₁to R₂₀ and R₂₁ and R₂₂ may pair and join together directly or throughanother atom to form a saturated or unsaturated bond in a cyclicstructure, any one of R₁₁ to R₁₅ and any one of R₁₆ to R₂₀ arerespectively bonded to the nitrogen atom in the imide skeleton, and anyone of R₁ to R₅ and any one of R₆ to R₁₀ join together directly orthrough another atom to form a saturated or unsaturated bond in a cyclicstructure.

The structural formula (A) in the aforementioned general formula (1) ispreferably a divalent residue of an organic group containing a fluoreneskeleton represented by the following structural formula (B)

wherein R₁ to R₄ and R₇ to R₂₀ are as defined in the strucutral formula(A); more preferably, at least one substituent selected from R₁₁ to R₂₀is modified by a functional group in the structural formula (B).

Moreover, this invention relates to resin materials for gas separationbase comprising polymers whose hydrogen atoms in the side-chain benzyland/or ally position are halogenated at a rate of modification of 34% ormore and, preferably, to resin materials for gas separation base whereinsaid polymers are polyimides.

Thus, this invention relates to cardo polymers whose hydrogen atoms inthe side-chain benzyl and/or allyl position are halogenated at a rate ofmodification of 0.1% or more, preferably to cardo polymers wherein saidpolymers are polyimides, and more preferably to polymers with a cardopolyimide structure represented by the following general formula (1)

wherein X is a divalent residue of an organic group and at least partlya divalent residue of an organic group represented by the followingstructural formula (A)

and Y is a tetravelent residue of an organic group; in the structuralformula (A), at least one of R₁ to R₂₀ is a halogen-modified substituentrepresented by

—CZR₂₁R₂₂

(wherein Z is a halogen atom and R₂₁ and R₂₂ will be defined later), theremainder of R₁ to R₂₀ and R₂₁ and R₂₂ in the halogen-modifiedsubstituent are hydrogen, halogen, linear or branched or cyclicunsubstituted or substituted alkyl, alkenyl, alkynyl, or aryl, theaformentioned alkyl, alkenyl, alkynyl and aryl groups may contain onekind or two kinds or more of hetero atoms selected from nitrogen,oxygen, sulfur, phosphorus and halogens and may be identical with ordifferent from one another, the aforementioned remainder of R₁ to R₂₀and R₂₁ and R₂₂ may pair and join together directly or through anotheratom to form a saturated or unsaturated bond in a cyclic structure, anyone of R₁₁ to R₁₅ and any one of R₁₆ to R₂₀ are respectively bonded tothe nitrogen atom in the imide skeleton, and any one of R₁ to R₅ and anyone of R₆ to R₁₀ join together directly or through another atom to forma saturated or unsaturated bond in a cyclic structure.

In polymers containing this cardo polyimide structure, it is preferablethat the structural formula (A) in the aforementioned general formula(1) is a divalent residue of an organic group having a fluorene skeletonrepresented by the following structural formula (B)

(wherein R₁ to R₄ and R₇ to R₂₀ are as defined earlier), at least onesubstituent selected from R₁₁ to R₂₀ is a halogen-modified substituent,and the rate of modification by halogen in the side-chain benzyl and/orallyl groups is 20% or more.

Moreover, this invention relates to polymers containing cardo polymerspossessing substituents at least one of which is a functionalgroup-modified substituent represented by

—CFuR₂₁R₂₂, —CFu₂R₂₁ and/or —CFu₃

(wherein Fu is a functional group or a derivative thereof which canreplace a halogen atom in the benzyl and/or ally position, R₂₁ and R₂₂are hydrogen, halogen, linear or branched or cyclic unsubstituted orsubstituted alkyl, alkenyl, alkynyl, or aryl, and the aforementionedalkyl, alkenyl, alkynyl or aryl group may contain one kind or two kindsor more of hetero atoms selected from nitrogen, oxygen, sulfur,phosphorus, and halogens, may be identical with or different from eachother, and may join together or to other carbon atoms directly orthrough another atom to form a saturated or unsaturated bond in a cyclicstructure); still more, this invention preferably relates to cardopolyimides possessing said functional group-modified substituents andfurther relates to resin materials for gas separation base containingsaid polymers and to gas separation membranes comprising said polymersand, more preferably, this invention relates to polymers containing acardo polyimide structure represented by the following general formula(1)

wherein X is a divalent residue of an organic group and at least partlya divalent residue of an organic group represented by the followingstructural formula (A)

and Y is a tetravalent residue of an organic group; in the structuralformula (A), at least one of R₁ to R₂₀ is a functional group-modifiedsubstituent represented by

—CFuR₂₁R₂₂, —CFu₂R₂₁ and/or —CFu₃

(wherein Fu is a functional group or a derivative thereof which canreplace a halogen atom in the benzyl and/or ally position), theremainder of R₁ to R₂₀ and R₂₁ and R₂₂ are hydrogen, halogen, linear orbranched or cyclic unsubstituted or substituted alkyl, alkenyl, alkynyl,or aryl, the aforementioned alkyl, alkenyl, alkynyl and aryl groups maycontain one kind or two kinds or more of hetero atoms selected fromnitrogen, oxygen, sulfur, phosphorus, and halogens and may be identicalwith or different from one another, the aforementioned remainder of R₁to R₂₀ and R₂₁ and R₂₂ may pair and join together directly or throughanother atom to form a saturated or unsaturated bond in a cyclicstructure, any one of R₁₁ to R₁₅ and any one of R₁₆ to R₂₀ arerespectively bonded to the nitrogen atom in the imide skeleton, and anyone of R₁ to R₅ and any one of R₆ to R₁₀ join together directly orthrough another atom to form a saturated or unsaturated bond in a cyclicstructure.

In the polymers containing this cardo polyimide structure, it ispreferable that the structural formula (A) in the aforementioned generalformula (1) is a divalent residue of an organic group possessing afluorene skeleton represented by the following structural formula (B)

(wherein R₁ to R₄ and R₇ to R₂₀ are as defined earlier) and at least onesubstituent selected from R₁₁ to R₂₀ is modified by a functional group.

Furthermore, this invention relates to a process for producing polymerscontaining a halogen-modified cardo polyimide structure from polymerscontaining a cardo polyimide structure represented by the followinggeneral formual (1)

wherein X is a divalent residue of an organic group and at least partlya divalent residue of an organic group represented by the followingstructural formula (A)

and Y is a tetravalent residue of an organic group; in the structuralformula (A), at least one of R₁ to R₂₀ is a pre-modification substituentrepresented by

—CHR₂₁R₂₂

(wherein R₂₁ and R₂₂ are as defined later), the remainder of R₁ to R₂₀and R₂₁ and R₂₂ are hydrogen, halogen, linear or branched or cyclicunsubstituted or substituted alkyl, alkenyl, alkynyl, or aryl, theaforementioned alkyl, alkenyl, alkynyl and aryl groups may contain onekind or two kinds or more of hetero atoms selected from nitrogen,oxygen, sulfur, phosphorus, and halogens and may be identical with ordifferent from one another, the aforementioned remainder of R₁ to R₂₀and R₂₁ and R₂₂ may pair and join together directly or through anotheratom to form a saturated or unsaturated bond in a cyclic structure, anyone of R₁₁ to R₁₅ and any one of R₁₆ to R₂₀ are respectively bonded tothe nitrogen atom in the imide skeleton, and any one of R₁ to R₅ and anyone of R₆ to R₁₀ join together directly or through another atom to forma saturated or unsaturated bond in a cyclic structure; said processcomprises treating said polymers containing a cardo-type polyimidestructure with a halogenating agent in mole equivalent corresponding to0.01-3 times that of the hydrogen atoms in the benzyl and/or allylposition in said pre-modification substituent and effecting the reactionat a rate of modification by halogen of 0.1% or more to give polymerscontaining halogen-modified substituents represented by

—CZR₂₁R₂₂

(wherein Z is a halogen atom and R₂₁ and R₂₂ are as defined earlier).

In the process for producing these polymers, it is preferable that thestructural formula (A) in the aforementioned general formula (1)possesses a fluorene skeleton represented by the following structuralformula (B)

(wherein R₁ to R₄ and R₇ to R₂₀ are as defined earlier), at least onesubstituent selected from R₁₁ to R₂₀ is a halogen-modified substituent,and the rate of modification by halogen of the hydrogen atoms in theside-chain benzyl and/or ally position is 20% or more.

Furthermore, this invention relates to a process for producing polymerscontaining a functional group-modified cardo polyimide structure frompolymers containing a cardo polyimide structure represented by thefollowing general formual (1)

wherein X is a divalent residue of an organic group and at least partlya divalent residue of an organic group represented by the followingstructural formula (A)

and Y is a tetravalent residue of an organic group; in the structuralformula (A), at least one of R₁ to R₂₀ is a pre-modification substituentrepresented by

—CHR₂₁R₂₂

(wherein R₂₁ and R₂₂ are as defined later), the remainder of R₁ to R₂₀and R₂₁ and R₂₂ in the pre-modification substituent are hydrogen,halogen, linear or branched or cyclic unsubstituted or substitutedalkyl, alkenyl, alkynyl, or aryl, the aforementioned alkyl, alkenyl,alkynyl, and aryl groups may contain one kind or two kinds or more ofhetero atoms selected from nitrogen, oxygen, sulfur, phosphorus, andhalogens and may be identical with or different from one another, theaforementioned remainder of R₁ to R₂₀ and R₂₁ and R₂₂ may pair and jointogether directly or through another atom to form a saturated orunsaturated bond in a cyclic structure, any one of R₁₁ to R₁₅ and anyone of R₁₆ to R₂₀ are respectively bonded to the nitrogen atom in theimide skeleton, and any one of R₁ to R₅ and any one of R₆ to R₁₀ jointogether directly or through another atom to form a saturated orunsaturated bond in a cyclic structure; said process comprises treatingsaid polymers containing a cardo polyimide structure with a halogenatingagent in mole equivalent corresponding to 0.01-3 times that of thehydrogen atoms in the benzyl and/or allyl position in the aforementionedpre-modification substituent, effecting the reaction at a rate ofmodification by halogen of 0.1% or more to give polymers containinghalogen-modified substituents represented by

—CZR₂₁R₂₂

(wherein Z is a halogen atom and R₂₁ and R₂₂ are as defined earlier),and then treating the polymers thus obtained with a nucleophilic reagentcontaining a functional group which can replace the halogen atom in thehalogen-modified substituent thereby converting at least partially theaforementioned halogen-modified substituents to functionalgroup-modified substituents represented by

—CFuR₂₁R₂₂, —CFu₂R₂₁ and/or —CFu₃

(wherein Fu is a functional group or a derivative thereof which canreplace a halogen atom in the benzyl and/or allyl position).

In this invention, the side-chain benzyl position is used in the sameway as in general organic systhesis; the side-chain benzyl positionrefers to the position where the carbon atom of the side-chain alkylgroup is directly bonded to the aromatic carbon and hydrogen in thebenzyl position designates the hydrogen directly bonded to the carbon inthe benzyl position. Likewise, as used in general organic synthesis, theallyl position refers to the position where carbon atoms forming anallylic carbon-carbon double bond are present and hydrogen in the allylposition designates the hydrogen directly bonded to the carbon in theallyl position.

The side-chain benzyl and/or allyl position as used in this inventionmay be present at any site in a polymer molecule and either one or bothof the benzyl and allyl positions may be present not only in the sidechains but also in the polymer backbone. Moreover, the allyl position isnot necessarily in the side chain of an aromatic ring. The side-chainbenzyl and/or allyl position as used in this invention may be present,for example, in X or Y in the general formula (1) or in any one of R₁ toR₂₂ in the structural formulas (A) and (B); also, they may be present inother parts of the polymers containing the foregoing. Furthermore,nothing would prevent the side-chain benzyl and/or allyl position asused in this invention from existing in plural number or existingtogether in a given polymer chain. For example, an allyl group may bepresent at the end of the benzyl group of R₁ to R₂₀ in the structuralformulas (A) and (B) and, still more, a benzyl and/or allyl group may bepresent at the end of this allyl group.

In the halogenation of this invention to be effected in the side-chainbenzyl and/or allyl position, it is not necessary to halogenateuniformly in all the benzyl and/or allyl positions in the repeating unitand it is allowable to effect halogenation only in some of the repeatingunits. In the cases where a plural number of hydrogen atoms are presenton benzyl and/or allyl carbon, it does not make difference whether thehalogenation occurs at either one of the benzyl and allyl carbons or thehalogenation occurs partially or wholly.

Halogen-modified polymers as used in this invention include thoseobtained by halogenating polymers and those obtained by polymerizingmonomers containing halogen in the side-chain benzyl and/or allyposition and raw material monomers or polymers may contain halogen fromthe start.

The rate of modification by halogen in this invention refers to the rateof the number of halogen atoms directly bonded to “the total carbonatoms in the benzyl and/or allyl position in the polymer” to the numberof hydrogen and halogen atoms bonded in the same manner and isrepresented by the following equation:

Rate of modification by halogen (%)=[(number of halogen atoms directlybonded to all the carbon atoms in the benzyl and/or allyl position inthe polymer)/(number of hydrogen and halogen atoms directly bonded toall the carbon atoms in the benzyl and/or allyl position in thepolymer)]×100

The number of those atoms required for the calculation can be determinedeasily by elemental analysis or ¹H-NMR analysis. Where the structure iscomplicated, ¹³C-NMR analysis readily allows the quantitativedetermination of the carbon atoms in the benzyl and allyl positions.

In this invention, cardo polymers generically refer to those polymers inwhich a cyclic group is directly linked to the polymer backbone. Thecyclic portion may contain a saturated or unsaturated bond involvingcarbon and other atoms such as nitrogen, oxygen, sulfur, and phosphorus;moreover, the cyclic portion may be polycyclic, linked to other carbonchains, or corsslinked.

Any polymers containing at least partly the aforementioned cardopolymers are acceptable as polymers containing the cardo polymerstructure of this invention and they may be copolymers with othermonomers, graft polymers, or crosslinked polymers. Resin materials ofthis invention refer to materials containing the aforementioned polymersand include a combination thereof with other materials or a blend orcomposite thereof with other materials.

Gas separation base of this invention may be in any shape as long as itis suited for the purpose of gas separation; the base may come in such ashape as membrane, hollow fiber, granule, sheet and bulk or it may befibers woven into cloth, filled randomly, or molded into pleats.Moreover, the base in question may be joined to, bonded by adhesive to,or blended with other materials or may be filled in containers of somesort.

Polyimides of this invention are represented by the aforementionedstructural formula (1) and, in the cases where they are simply referredto as polyimides, X may be a divalent residue of any organic group.Tetracarboxylic acid dianhydrides, the raw material for Y, includepyromellitic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic aciddianhydride, bis(3,4-dicarboxy-phenyl)sulfone dianhydride,2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride,3,3′,4,4′-biphenyltetracarboxylic acid dianhydride,3,3′,4,4′-tetracarboxydiphenylether dianhydride, and2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, and a mixture of thesedianhydrides and they may contain benzyl and/or allyl groups.

Polymers of this invention or polymers to be used for their preparationare synthesized by a general synthetic procedure for polymers. Polymersof any kind are acceptable if they can be used for functional materials,particularly for gas separation base, but they need to contain halogenatoms in the side-chain benzyl and/or allyl position or hydrogen atomsreplaceable with halogen atoms in the benzyl and/or allyl position atleast in a part of their structure. For example, polymers with thefollowing basic skeleton or their mixtures, copolymers, and crosslinkedpolymers can be used on condition that they meet the aforementionedrequirement.

(1) Polymers in which the Carbon-carbon Bond Forms the Backbone Chain

Polyolefins (polyethylene, polypropylene, poly-1-butene, etc.),polystyrene, polyacetylenes, polyphenylenes, and polysaccharides such ascellulose.

(2) Polymers Containing Oxygen in the Backbone Chain

Polyethers (—O—), polyacetals (—O—R—O—R′—), polyesters (—COO—),polycarbonates (—O—CO—O—), etc.

(3) Polymers Containing Nitrogen in the Backbone Chain

Polyamines (in particular, polyamines in which H of —NH— is replaced byan alkyl group or the like), polyamides (—NH—CO—), polyurethanes(—OCONH—R—NHCOO—R′—), polyureas (—NHCONH—R—NHCONH—R′—), polyimides,polyimidazoles, polyoxazoles, polypyrroles, polyanilines, etc.

(4) Polymers Containing Sulfur in the Backbone Chain

Polysulfides (—C—S—C—), polysulfones (—C—SO₂—C—), etc.

(5) Polymers Containing Phosphorus in the Backbone Chain

Polyphoshpines (—PR—), polyphosphine oxides [—PR(═O)—], polyphosphinates[—OPR(═O)—], polyphosphonates [—OPR(═O)—O—], etc.

(6) Polymers Containing Metal in the Backbone Chain

Polysiloxanes (—SiRR′O—), polysilanes (—SiRR′—), etc.

Polymers of this invention, if they contain halogen atoms in theside-chain benzyl and/or allyl position or hydrogen atoms replaceable byhalogen in the side-chain benzyl and/or allyl position, can have askeleton selected from, for example, polyesters, polycarbonates,polyethers and polyimides described in Japan Kokai Tokkyo Koho Hei10-99,666 (1998).

In this invention, halogen-modified polymers can be prepared bypolymerizing monomers containing halogen atoms in the side-chain benzyland/or allyl position (while protecting the benzyl and/or allyl positionand other positions as needed) or halogenating polymers containinghydrogen atoms replaceable by halogen in the side-chain benzyl and/orallyl position by treating with a position-selective halogenating agentunder radical reaction conditions according to a normal organicsynthetic procedure. Halogenating agents which are capable of effectinghalogenation in the side-chain benzyl position or in the allyl positionof aromatic compounds are useful and they include N-bromosuccinimide(NBS), N-chlorosuccinimide (NCS), N-iodosuccinimide (NIS), sulfurylbromide (SO₂Br₂), sulfuryl chloride (SO₂Cl₂), t-butyl hypohalite,bromine, and 1,3-dibromo-5,5-dimethyl-hydantoin (DBMH). The halogenationin the aforementioned reaction proceeds selectively in the side-chainbenzyl and/or allyl position preferably under the radical reactioncondition and this condition can be attained by high temperature,irradiation by UV, use of a nonpolar solvent, and addition of a radicalgenerator.

The halogenation of this invention in the side-chain benzyl position ispreferably bromination because of the ease of controlling the reactionand the rate of modification by bromine, and NBS is suited as abrominating agent for this reaction, in particular, for the brominationin the allyl position.

The method for preparing the aforementioned halogen-modified polymers isapplicable to the case where the polymers are polyimides or cardopolymers.

Cardo polymers in this invention include polymers of a vinyl monomersuch as an alkyl-substituted derivative of methylidenephthalide,polycarbonates resulting from the reaction of a bisphenol such as analkyl-substituted derivative of 9,9-bis(4′-hydroxyphenyl)anthrone-10with phosgene, and polyamides resulting from the reaction of analkyl-substituted derivative of 3,3-bis(4′-carboxyphenyl)phthalide witha diamine.

In this invention, halogen-modified cardo polyimides are synthesized inthe following manner.

The raw material cardo polyimides for the synthesis of halogen-modifiedcardo polyimides are obtained by the reaction of a diamine whichgenerates the X component in the general formula (1) with atetracarboxylic acid dianhydride which generates the Y component in thegeneral formula (1). It is necessary in this reaction that hydrogenatoms are present in the side-chain benzyl and/or allyl position in atleast one of X or Y.

Any diamine having a cardo skeleton is useful as a diamine generatingthe X component in the general formula (1); for example,9,9-bis(4′-aminophenyl)-phthalimidine and1,1-bis(4′-aminophenyl)cyclohexane, a mixture of the two, and a mixtureof the two and other diamines.

A diamine generating the X component in the general formula (1) ispreferably an aromatic cardo monomer represented by the structuralformula (A); for example, 9,9-bis(4′-aminophenyl)fluorene,9,9-bis(4′-aminophenyl)-anthrone-10, a mixture of the two, and a mixtureof the two and other diamines.

A diamine generating the X component in the general formula (1) is morepreferably a diamine having a xylidine skeleton which is a compoundrepresented by the structural formula (A) wherein R₁₃ and R₁₈ are aminogroups, R₁₁, R₁₂, R₁₄ through R₁₇, R₁₉, and R₂₀ are hydrogen atoms,functional groups such as alkyl groups represented by —C_(n)H_(2n+1) (nis an integer, preferably 1-4), alkoxyl groups represented by—OC_(n)H_(2n+1) (n is an integer, preferably 1-4), carboxyl groups,carboxymethyl groups, and nitro groups, and halogen atoms, either usedsingly or together with other diamines.

Concrete examples of diamines with a xylidine skeleton are derivativesof fluorene such as 9,9-bis(3′,5′-dimethyl-4′-aminophenyl)fluorene,9,9-bis(2′,3′-dimethyl-4′-aminophenyl)fluorene,9,9-bis(3′,6′-dimethyl-4′-aminophenyl)fluorene,9,9-bis(2′,6′-dimethyl-4′-aminophenyl)fluorene,9,9-bis(3′,5′-dimethyl-2′,6′-difluoro-4′-aminophenyl)fluorene,1,2,3,4,5,6,7,8-octafluoro-9,9-bis(3′,5′-dimethyl-2′,6′-difluoro-4′-aminophenyl)fluorene,9,9-bis(3′,5′-dimethyl-4′-aminophenyl)fluorene-4-carboxylic acid, methyl9,9-bis(3′,5′-dimethyl-4′-aminophenyl)fluorene-4-carboxylate,4-bromo-9,9-bis(3′,5′-dimethyl-4′-aminophenyl)fluorene,4-nitro-9,9-bis(3′,5′-dimethyl-4′-aminophenyl)fluorene, methyl9,9-bis(3′,5′-dimethyl-4′-aminophenyl)fluorene-4-sulfonate, and4,5-dimethyl-9,9-bis(3′,5′-dimethyl-4′-aminophenyl)fluorene and amixture thereof.

Other diamines include those containing aromatic residues such as9,9-bis(4′-aminophenyl)fluorene, 9,9-bis(2′-aminophenyl)fluorene,9,9-bis(3′,5′-diethyl-4′-aminophenyl)fluorene,9,9-bis(3′-methyl-4′-aminophenyl)fluorene,9,9-bis(3′-methyl-5′-ethyl-4′-aminophenyl)fluorene,9,9-bis(3′,5′-di-n-butyl-4′-aminophenyl)fluorene,9,9-bis(3′,5′-di-s-butyl-4′-aminophenyl)fluorene,9,9-bis(3′-bromo-4′-aminophenyl)fluorene,4-chloro-9,9-bis(3′,5′-diethyl-4′-aminophenyl)fluorene,4-nitro-9,9-bis(3′,5′-diethyl-4′-aminophenyl)fluorene,9,9-bis-(2′,5′-diethyl-4′-aminophenyl)fluorene,9,9-bis[3′,5′-di-(3″-butene)-4′-aminophenyl]fluorene,9,9-bis(4′-aminophenyl)fluorene-4-carboxylic acid, methyl9,9-bis(4′-aminophenyl)fluorene-4-carboxylate, methyl9,9-bis(4′-aminophenyl)fluorene-4-sulfonate, 2,7-diaminofluorene,naphthalenediamine, 2,8-diaminobenxofuran, 4,4′-diaminobiphenyl, and4,4′-diaminodiphenyl ether and those containing aliphatic residues suchas hexamethylenediamine and isopropyldiamine.

In the use of other diamines, there is no specific restriction imposedon the proportion of other diamines to the diamines having a xylidineskeleton, but it is desirable for the proportion to be 90 mol % or less.

Tetracarboxylic acid dianhydrides generating the Y component in thegeneral formula (1) include pyromellitic dianhydride,3,3′,4,4′-benzophenonetetracarboxylic acid dianhydride,bis(3,4-dicarboxyphenyl)sulfone dianhydride,2,2-bis(3′,4′-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropanedianhydride, 3,3′,4,4′-biphenyltetracarboxylic acid dianhydride,3,3′,4,4′-tetracarboxydiphenylether dianhydride and a mixture thereof.

The cardo polyimides obtained in this manner are modified by treatingwith a halogenating agent to replace the hydrogen atoms in theside-chain benzyl and/or allyl position with halogen atoms.

The halogenation reaction of the cardo polyimides in the side-chainbenzyl position is explained with reference to the aforementionedbromination with the use of NBS. The reaction is generally applicable tothe halogenation in the side-chain benzyl and/or allyl position ofpolymers.

The bromination reaction in question is a radical reaction that isaccelerated in a halogen-containing solvent by heating and/orultraviolet irradiation preferably in the presence of 0.1˜1% of aradical initiator and molecular bromine being generated from NBS in lowconcentration participates in the reaction. A preferablehalogen-containing solvent is carbon tetrachloride, chloroform,methylene chloride, or 1,2-dichloroethane. The reaction is acceleratedby heat, light, or a radical initiator such as benzoyl peroxide andazobisisobutyronitrile (AIBN).

The bromine-modified cardo polyimides obtained in this reaction areisolated and purified by adding the reaction mixture to a solvent suchas methanol to separate polyimides, pulverizing the polyimides suitably,washing with a solvent such as methanol, and drying under reducedpressure at a temperature in the range from room temperature to 60° C.The halogenation takes place easily in the side-chain benzyl and/orallyl position.

The rate of modification by bromine of the bromine-modified cardopolyimides as defined earlier can be calculated readily on the basis ofelemental analysis or ¹H-NMR and ¹³C-NMR analysis.

The following example illustrates the bromination in the side-chainbenzyl position. In the case of the modification by bromine of cardopolyimides [PI-BPBA-BAFL(4Me)] prepared by polymerizing the monomerrepresented by the structural formula (B) in which R₁₃ and R₁₈ are aminogroups, R₁₂, R₁₄, R₁₇, and R₁₉ are methyl groups, and the rest of R'sare hydrogen and 3,3′,4,4′-biphenyltetracarboxylic acid dianhydride, therate of modification by bromine can be calculated from the ratio of theintegrated values of methylene protons in the benzyl position resultingfrom monobromination [δ: in the vicinity of 4.0-4.8 ppm (—CH₂—Br), br-m,2H], methylidyne proton in the benzyl position resulting fromdibromination [δ: in the vicinity of 6.5 ppm (—CH—Br₂), br-s, 1H], andmethyl protons in the tolyl group in the absence of bromination [δ: inthe vicinity of 1.8-2.4 ppm (—CH₃), br-m, 3H] determined by ¹H-NMRanalysis (300 MHz, CDCl₃, room temperature). For example, in case theintegrated values of the peaks of methylene protons in the benzylposition, methylidyne proton in the benzyl position, and methyl protonsin the tolyl group are respectively 10.0, 1.0, and 6.0, the rate ofmodification by bromine is calculated as follows:

Rate of modification by bromine(%)=[10.0/(2×1)+1.0/(1×2)]/[10.0/(2×3)+1.0/(1×3)+6.0/(3×3)]×100=29

This means that, of the twelve hydrogen atoms in the four methyl groups,namely, R₁₂, R₁₄, R₁₇, and R₁₉ in the structural formula (B), 3.5(12×0.29) hydrogen atoms on the average per repeating unit of thepolymer are replaced by bromine atoms.

Likewise, in the case of the bromination in the allyl position, the rateof modification by bromine can be calculated from the ratio of theintegrated values of methylene protons in the allyl position resultingfrom monobromination [δ: in the vicinity of 3.7-4.3 ppm (—C═C—CH₂—Br),br-m, 2H], methylidyne proton in the allyl position resulting fromdibromination [δ: in the vicinity of 6.5 ppm ([—C═C—CHBr₂), br-m,1H],and methyl protons in the allyl position in the absence of bromination[δ: in the vicinity of 1.5-2.4 ppm (—C═C═CH₃), br-m, 3H] determined by1H-NMR analysis (300 MHz, CDCl₃, room temperature).

The rate of modification by halogen can be controlled at the desiredvalue by controlling the amount of a halogenating agent to be used forthe halogenation reaction and this makes it possible to prepare cardopolyimides at a desired rate of modification by halogen.

In this invention, halogen-modified cardo polyimides exhibiting a rateof modification by halogen of 0.1% or more, preferably 20% or more, morepreferably 34% or more, are prepared from cardo polyimides of theaforementioned general formula (1) by treating with a halogenating agentin mole equivalent normally 0.01-3 times, preferably 0.5-3 times, thatof total hydrogen atoms in the side-chain benzyl and allyl positions ofR₁ to R₂₀ in the structural formula (A). A rate of modification byhalogen of less than 0.1% undesirably produces a small halogenatingeffect. A rate of modification by halogen of 20% or more is desirableand this can be obtained under normal reaction conditions with apronounced effect of modification by halogen. Supposing methyl groups inthe benzyl position are halogenated, a rate of modification by halogenof 34% means the condition where one halogen atom or more on the averagehas entered each methyl group in the benzyl position and this conditionis particularly desirable. There is no specific upper limit for the rateof modification by halogen, but it is preferably 90% or less from aconsideration of the gas permeability. In the case of CO₂ separation,the gas permeability [P(CO₂)] is excellent at a low rate of modificationby halogen while the gas selectivity [α] improves at a high rate ofmodification by halogen. It is possible to prepare gas separationmembranes with a good balance of gas permeability [P(CO₂)] and gasselectivity [α] from halogen-modified cardo polyimides by controllingthe rate of modification by halogen. What is discussed above also holdsfor polymers in general.

Functional group-modified cardo polymers can be prepared readily bytreating the aforementioned halogen-modified cardo polymers with anucleophilic reagent possessing a functional group Fu which can replacea halogen atom in the benzyl and/or allyl position. Functional groups Fuof this kind are linear, branched, or cyclic unsubstituted orsubstituted alkyl groups, alkenyl groups, alkynyl groups, aryl groups,and heterocyclic groups and they may contain atoms other than carbonsuch as nitrogen, oxygen, sulfur, and phosphorus in the molecule.Moreover, they may contain polar functional groups capable of changingthe existing state of electrons, functional groups with a multiple bondcapable of inducing a π electron-π electron interaction, ororganometallic functional groups carrying metals with an empty orbit.

Concrete examples of functional groups Fu containing atoms other thancarbon are —OH, —OR₂₃, —OCOR₂₃, —OCSR₂₃, —NO₂, —NCO, —NCS, —CN,—CH(COR₂₃)(COR₂₄),halogen, —SR₂₄, —SR₂₄R₂₅, —SR₂₄R₂₅R₂₆, —SOR₂₄,—SOR₂₄R₂₅, —SOR₂₄R₂₅R₂₆, —SO₂R₂₄, —SO₂R₂₄R₂₅, —SO₂R₂₄R₂₅R₂₆, —SO₃R₂₄,—SO₃R₂₄R₂₅, —SO₃R₂₄R₂₅R₂₆, —PR₂₄, —PR₂₄R₂₅, —PR₂₄R₂₅R₂₆, —POR₂₄,—POR₂₄R₂₅, —POR₂₄R₂₅R₂₆, —PO₂R₂₄, —PO₂R₂₄R₂₅, —PO₂R₂₄R₂₅R₂₆, —PO₃R₂₄,—PO₃R₂₄R₂₅, —PO₃R₂₄R₂₅R₂₆, —SiR₂₄R₂₅R₂₆, —SnR₂₄R₂₅R₂₆, —PdR₂₄R₂₅R₂₆, and—GeR₂₄R₂₅R₂₆. In these examples, R₂₃ designates hydrogen, sulfur,phosphorus, linear, branched, or cyclic unsubstituted or substitutedalkyl, alkenyl, alkynyl, aryl, and heterocyclic and may containnitrogen, oxygen, or sulfur in the molecule. The groups R₂₄, R₂₅, andR₂₆ are hydrogen, oxygen, sulfur, phosphorus, linear, branched, orcyclic unsubstituted or substituted alkyl, alkenyl, alkynyl, aryl,alkoxy, or heterocyclic and they may contain nitrogen, oxygen, or sulfurin the molecule. It is possible to convert these substituents intofunctional groups containing protons of high acidity such as —COOH and—SO₃H.

Moreover, functional group-modified cardo polymers of this invention canserve as functional materials in a variety of end uses afterincorporation of crown ethers, optically active structures containingasymmetric carbon, metal complexes, and materials which can interactwith gases such as oxygen or of functional structures such as antibodiesand biomaterials.

The nucleophilic substitution reaction with the use of a nucleophilicreagent described above is generally considered to proceed with thehalogenated carbon in the benzyl and/or allyl position inhalogen-modified cardo polymers undergoing S_(N)1 or S_(N)2 subsitutionin the presence of a carbanion, an anion of oxygen, nitrogen, sulfur orphosphorus, or a nucleophilic reagent containing an atom with a lonepair of electrons. The halogenated carbon atom in the benzyl and/orallyl position in halogen-modified cardo polymers is readily attacked bya nucleophilic reagent under the alkaline conditions or in the presenceof a phase-transfer catalyst such as tetrabutylammonium chloride,polyamine, and crown ether to allow replacement of the halogen atom by afunctional group.

Another procedure for introducing a functional group Fu tohalogen-modified cardo polymers is to prepare an RMgX-typeorganomagnesium compound, the so-called Grignard reagent, from thepolymers and treat the Grignard reagent with any of reactants that arecapable of undergoing Grignard reactions such as alcohols, water,aldehydes, ketones, esters, carbon dioxide, and amines.

As a concrete example, the introduction of an alkyl group can beeffected in a reaction system in which the carbanion is lithiated by LDA(lithium diisopropylamide) and used in the substitution reaction or in areaction system in which a two-layer reaction is carried out with theuse of solid potassium hydroxide and a phase-transfer catalyst such astriethylammonium chloride.

The introduction of an amino group (—NR₁₃R₁₄) can be effected bydirectly treating halogen-modified cardo polymers with twice or more inmole equivalent of the corresponding primary or secondary amine insolution thereby replacing the halogen atoms with the amino groups. Incase the amine used is primary, each of its two active hydrogen atomsparticipates in the substitution reaction with the possibility offorming a crosslinked structure; it is then advisable to dilute thepolymers with a solvent and use a large excess of the amine.

A hydroxyl group (—OH) can be introduced by a solid-liquid orliquid-liquid two-phase reaction; for example, in a reaction system inwhich hydrolysis is carried out under the basic conditions or in theco-presence of a silver salt, in a reaction system in which the reactionis carried out in solution with the use of solid potassium hydroxide orthe like and a phase-transfer catalyst such as triethylammoniumchloride, or in a reaction system in which an aqueous solution oftetra-n-butylammonium hydroxide or the like is allowed to coexist in thetheoretical amount. Moreover, the group —OR₂₃ can be introduced bytreating the corresponding unsubstituted or substituted alcohol orphenol with sodium to form the sodium salt and treating thehalogen-modified cardo polymers with the sodium salt in solution in thepresence of a phase-transfer catalyst such as triethylammonium chloride.

A sulfur-containing functional group Fu such as sulfonyl (—SO₂R₂₃),sulfinyl (—SOR₂₃), mercapto (—SR₂₃), —OCSR₂₃, and —NCS can be introducedby converting the corresponding thiol, sulfonic acid, sulfinic acid,sulfenic acid, mercaptan, thiophenol, thiocarboxylic acid, azasulfoniumsalt, sulfilimine, and sulfoximine to the sodium or potassium salt andsubmitting the salt to the reaction in solution in the presence of aphase-transfer catalyst such as triethylammonium chloride. Furthermore,the group —SO₃H can be introduced by oxidizing modified polymerscarrying —SH or with the use of Na₂SO₃ and a phase-transfer catalyst.

The groups —OCOR₂₃, —NO₂, —NCO, and —CN can be introduced readily byconverting the corresponding carboxylic acid and the like to the sodiumor potassium salt and submitting the salt to the reaction in solution inthe presence of a phase-transfer catalyst such as triethylammoniumchloride.

Of the aforementioned functional groups Fu, —NO₂, —NCO, —NCS, and —CNare commercially available as quaternary ammonium salts containing therespective anion as counter ion and such quaternary ammonium salts areuseful for the introduction of these groups. Moreover, —COOH can bederived from modified polymers containing —CN by hydrolysis with the useof sulfuric acid and the like.

A phosphorus-containing functional group Fu is introduced by using asreactant the sodium or potassium salt of a trivalent organophosphoruscompound such as phosphine, phosphinous acid, phosphonous acid, andphosphorous acid and a pentavalent organophosphorus compound such asphosphorane, phosphine oxide, phosphinic acid, phosphonic acid, andphosphoric acid.

Halogens include fluorine, chlorine, bromine, and iodine and they can beintroduced in a system involving potassium fluoride, potassium chloride,potassium bromide or potassium iodide and a phase-transfer catalyst.

As described above, a halogen atom can be introduced directly bytreating cardo polymers with a suitable halogenating agent, but anotherapproach is to introduce a suitable halogen atom, preferably bromine, togive intermediate halogen-modified cardo polymers first and to replacethe halogen by another halogen in a reaction system in which theintermediate halogen-modified cardo polymers are treated with potassiumfluoride, potassium chloride or potassium iodide in the presence of aphase-transfer catalyst.

In the aforementioned reaction system in which a phase-transfer catalystis used, it is possible to effect the substitution reaction in questionby supporting the phase-transfer catalyst on the resin and allowing thesupported catalyst to coexist in the reaction system. This procedurehelps to facilitate the treatment for purification after the reaction.

In the introduction of the aforementioned functional groups Fu, there isno specific restriction on the reactants to be used in the substitutionreaction as long as they contain an appropriate functional group Fu inthe molecule and they may be saturated, unsaturated, linear, branched orcyclic and they may additionally contain atoms other than carbon, forexample, hydrogen, nitrogen, oxygen, sulfur, and halogen without illeffect. In case there are two or more functional groups Fu, eitheridentical with or different from each other, in the reactant molecules,each functional group participates in the substitution reaction; as aresult, there is the possibility of crosslinking taking place inside asingle polymer chain or between different polymer chains inhalogen-modified cardo polymers and the crosslinking can produce theeffect of improving the strength of polymers and the performance of gasseparation membranes.

Furthermore, the reaction of halogen-modified cardo polymers with anucleophilic reagent to give functional group-modified cardo polymers isnot restricted to the chemical reaction in bulk and it is possible toutilize this nucleophilic substitution reaction as a procedure forsurface treatment after molding the halogen-modified cardo polymers intofilm or hollow fiber.

In case the halogen atoms in the benzyl position remain unreacted in thefunctional group-modified cardo polymers after the reaction ofhalogen-modified cardo polymers with a nucleophilic reagent, they can beremoved by a known procedure for dehalogenation such as heating, ifnecessary. While the procedure is being applied, a carbon-carbon bondmay possibly form inside a polymer chain or between different polymerchains to give a crosslinked structure which produces an extra effect ofimproving the strength of polymers and the performance of gas separationmembranes.

A proper selection of functional groups to be introduced as functionalgroup Fu in this invention makes it possible to produce resin materialscontaining polymers of this invention useful not only for gas separationbut also for selective separation or selective transfer of liquids, avariety of solutes dissolved in liquids (dissolved solids, dissolvedgases, ions, etc.), mixtures, and dispersions. That is, introduction ofa functional group that exhibits a highly selective interaction with anobject of separation or transfer yields a support capable of selectivelyseparating or transfering said object.

Modified cardo polymers of this invention, that is, cardo polymersmodified by halogen or functional group, exhibit excellent propertiescommon to cardo polymers, particularly excellent solvent solubility andease of wet molding, and are soluble in N-methyl-2-pyrrolidone (NMP),dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), dimethylformamide(DMF), p-chlorophenol, tetrahydrofuran (THF), and a variety ofchlorinated solvents (chloroform; methylene chloride,1,2-dichloroethane, etc.). Halogen-modified cardo polymers, particularlybromine-modified cardo polymers, improve their solvent solubility inresponse to the rate of modification by halogen and this permits asuitable selection of the kind and amount of solvent to be used in thepreparation of membranes. Moreover, halogen-modified cardo polymers,particularly bromine-modified cardo polymers, are dissolvedhomogeneously in an organic solvent and treated with a nucleophilicreagent to replace the halogen with a functional group and this makes itpossible to effect the desired modification by a functional group tosuit the target gas to be separated.

In this invention, no restriction is imposed on the geometrical shape ofgas separation membranes molded from modified cardo polymers representedby the aforementioned general formula (1) as long as the membranes arein any of the shapes generally used for gas separation. The structure ona micro scale is symmetric or asymmetric or a composite of a thincoating on the porous membrane. A known procedure is applicable to theproduction of membranes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the results of ¹H-NMR analysis conducted onthe bromine-modified cardo polyimides [PI-BPDA-BAFL(4Me)-Br(27.6%)]prepared in Example 1.

FIG. 2 is a graph showing the results of ¹³C-NMR analysis conducted onthe bromine-modified cardo polyimides [PI-BPDA-BAFL(4Me)-Br(27.6%)]prepared in Example 1.

FIG. 3 is a graph showing the relationship between the amount of NBSused [molar ratio (NBS/12H)] and the rate of modification by bromine inthe bromination reactions carried out in Examples 1 to 10 and 22 to 26.

FIG. 4 is a graph showing the relationship between the rate ofmodification by bromine and the gas selectivity (α, CO₂/N₂ separationfactor) in Examples 7 to 10 and Comparative Example 3.

FIG. 5 is a graph showing the relationship between the rate ofmodification by bromine and the gas permeability [P(CO₂)] in Examples 7to 10 and Comparative Example 3.

PREFERRED EMBODIMENTS OF THE INVENTION

The preferred modes of the execution of this invention will be describedconcretely below with reference to Examples and Comparative Examples.

In the following Examples and Comparative Examples, the permeabilitycoefficient of gas was determined on the feed gas which was a mixture of10% carbon dioxide and 90% nitrogen at 35° C. (308 K) and at a pressuredifference of 1 atmosphere (1.0×10⁵ Pa) by the time lag method with theaid of a reduced pressure type apparatus for measuring the rate ofpermeation of gas equipped with a gas chromatograph as a detector. Thefilm for testing was mounted on the apparatus and dried for about 2hours at 90° C. under high vacuum. Although the permeability coefficientof gas (P) is expressed in the unit of m³·m/(m²·s·Pa), it is alsoexpressed simultaneously in the unit of barrer as follows.$\begin{matrix}{{1\quad {barrer}} = {1 \times 10^{- 10}\quad {cm}^{3}\quad ({STP})\quad {{cm}/\left( {{{cm}^{2} \cdot s \cdot {cm}}\quad {Hg}} \right)}}} \\{= {7.5 \times 10^{- 18}\quad {m^{3} \cdot {m/\left( {m^{2} \cdot s \cdot {Pa}} \right)}}\quad \left( {{standard}\quad {condition}} \right)}}\end{matrix}$

The separation factor (α) is expressed by the ratio of permeabilitycoefficients.

Where a structural formula is shown in any one of the followingexamples, it is merely an average structure to be inferred from theresults of NMR determination and there is no denying that otherstructures may be present.

EXAMPLE 1

In 5,500 g of N-methyl-2-pyrrolidone (NMP) were dissolved 650 g (1.59moles) of 9,9-bis(3′,5′-dimethyl-4′-aminophenyl)fluorene [BAFL(4Me)] and468 g (1.59 moles) of 3,3′,4,4′-biphenyltetracarboxylic acid dianhydride(BPDA) by stirring for 1 hour at room temperature and the solution waskept at 180° C. and allowed to react for 7 hours with removal of thewater being formed. Upon completion of the reaction, the reactionmixture was diluted by fresh addition of 18 liters of NMP, cooled, andpoured into 100 liters of methanol to for a precipitate.

The precipitate was washed twice with 50 liters of methanol and driedunder vacuum at 70° C. for 2 days and at 100° C. for 1 day to give 980 gof cardo polyimided [PI-BPDA-BAFL(4Me); molecular weight of therepeating unit, 662.7] represented by the following structural formula.

In 500 ml of 1,2-dichloroethane was dissolved 26.5 g (40 millimoles) ofthe PI-BPDA-BAFl(4Me) by stirring for 1 hour at room temperature, 51.3 g(288 millimoles) of N-bromosuccinimide (NBS) and 0.5 g of2,2-azobisbutyronitrile (AIBN) were added, and the mixture was allowedto react for 5 hours under reflux conditions (the temperature of thesolution being 80-100° C.). Upon completion of the reaction, thereaction mixture was poured into 4.5 liters of methanol to precipitatepolymers. The polymers thus precipitated were collected, washed withgrinding in a mixer after fresh addition of 1 liter of methanol, andfurther washed 5 times with 1.5 liters of methanol. Thereafter, thepolymers were dried under vacuum at 50° C. for 12 hours to givebromine-modified PI-BPDA-BAFL(4Me).

The bromine-modified polymers thus obtained were submitted to ¹H-NMRanalysis (300 MHz, CDCl₃, room temperature), ¹³C-NMR analysis (75 MHz,CDCl₃, room temperature), two-dimensional NMR analysis, and elementalanalysis of bromine. The results of the ¹H-NMR and ¹³C-NMR analyses arerespectively shown in FIGS. 1 and 2. The results of ¹H-NMR analysisindicate that the integraded value of peak x (δ: 4.1-4.4 ppm, br-m) ofthe methylene protons (Ar—CH₂—Br) in the benzyl position aftermonobromination is 2.0 and the integrated value of peak a (δ: in thevicinity of 1.9-2.2 ppm, br-m) of the methyl protons (Ar—CH₃) in thebenzyl position in the absence of bromination is 0.79 and this confirmsthat the side-chain methyl group on the aromatic ring in the BAFL(4Me)segment of the polymer is partly monobrominated. In addition, peak y (δ:6.3-6.6 ppm, br-m) was observed. In comparison with the referencecompound benzal bromide (Ar—CH—Br₂: δ 6.6-6.7 ppm, br-s), the peak y wasinferred to be due to the methylidyne proton (Ar—CH—Br²) in the benzylposition after dibromination. On the other hand, in the ¹³C-NMRanalysis, peak X (δ, 29.7 ppm) of the methylene carbon (Ar—CH₂—Br) inthe benzyl position after monobromination and peak A (δ, in the vicinityof 18 ppm) of the methyl carbon (Ar—CH₃) in the benzyl position in theabsence of bromination were observed and, in addition, peak Y (δ, in thevicinity of 34.5 ppm) was observed. The peak Y was inferred to be due tothe methylidyne carbon (Ar—CH—Br₂) in the benzyl position afterdibromination in comparison with the reference compound benzal bromide(Ar—CH—Br₂; δ in the vicinity of 41 ppm). Each peak was assigned bytwo-dimensional NMR determination and, as a correlation was observedbetween a part of the peak y of 1H-NMR spectrum and the peak Y of¹³C-NMR spectrum, the peak y was assigned to the methylidyne proton andthe peak Y to the methylidyne carbon in the benzyl position (Ar—CH—Br₂)after replacement of the hydrogens in the side-chain methyl group withtwo bromine atoms. The integrated value of the portion which shows acorrelation between the peak y of ¹H-NMR spectrum and the peak Y of¹³C-NMR spectrum is 0.04 and the rate of modification by bromine is27.6% and this indicates that approximately 3.31 hydrogen atoms,averaged for the polymers, out of the 12 hydrogen atoms in the benzylposition in the repeating unit are replaced by bromine atoms. The¹³C-NMR analysis indicated the absence of tribrominated carbon in thebenzyl position. Since the integrated value of aromatic hydrogen and theabundance ratio of aliphatic hydrogen in the ¹H-NMR analysis are roughlyidentical with the calculated values, the possibility of bromine beingintroduced to the aromatic ring is considered to be remote, if any.

[¹H-NMR analysis]

Ar—CH—Br₂ (δ: 6.3-6.6 ppm, br-m; integrated value, 0.04)

Ar—CH₂—Br (δ: 4.2-4.4 ppm, br-m; integrated value, 2.00)

Ar—CH₃ (δ: 2.0-2.2 ppm, br-m; integrated value, 0.79)

[Rate of modification by bromine] 27.6%

[Elemental analysis of Br] Br: 31.6%

[Number of bromine introduced to the benzyl position per repeating unit]Approximately 3.31

As is apparent from the results of NMR analysis and elemental analysisof bromine, the bromine-modified polymers are bromine-modified cardopolyimides [PI-BPDA-BAFL(4Me)-Br] represented by the followingstructural formula.

Moreover, the results of ¹H-NMR analysis conducted on thebromine-modified polymers thus obtained indicate that the integratedvalues of the methylidyne proton in the benzyl position afterdibromination, the methylene protons in the benzyl position aftermonobromination, and the methyl protons in the tolyl group in theabsence of bromination are respectively 0.04, 2.00, and 0.79 and thisconfirms that the bromine-modified polymers in question arePI-BPDA-BAFL(4Me)-Br(27.6%) resulting from partial di- andmono-bromination of the methyl groups of the tolyl groups.

Hereinafter, bromine-modified cardo polyimides will be written using asymbol such as PI-BPDA-BAFL(4Me)-Br and the rate of modification bybromine will be written immediately thereafter in parentheses like(27.6%).

In 50 ml of NMP was dissolved 5 g of the PI-BPDA-BAFL(4Me)-Br(27.6%) atroom temperature and the resulting solution was cast on a glass plate ina uniform thickness and dried in a dryer at 50° C. for 10 hours. Then,the dried glass plate was immersed in distilled water and the film waspeeled off the glass plate and dried in a vacuum dryer at 50° C. for 3days. The film was then immersed in methanol to remove the solvent NMPcompletely and dried under vacuum at 50° C. for 24 hours. Thus, thebromine-modified cardo polyimides PI-BPDA-BAFL(4Me)-Br(27.6%) wereconverted into membrane.

Gas permeabilities of the membrane were as follows.

[Permeability coefficient of carbon dioxide]

647×10⁻¹⁸m³.m/(m².s.Pa) (86.2 barrer)

[Permeability coefficient of nitrogen]

18.0×10⁻¹⁸m³.m(m².s.Pa) (2.4 barrer)

[Carbon dioxide/nitrogen separation factor] 36

EXAMPLE 2

Using 26.5 g (40 millimoles) of the PI-BPDA-BAFL(4Me) prepared inExample 1 and 17.1 g (96 millimoles) of NBS, the bromination reaction,purification, and analysis were carried out as in Example 1.Approximately 10.2% of the 12 hydrogen atoms in the benzyl position inthe repeating unit, or approximately 1.22 hydrogen atoms, was replacedby bromine atoms to give bromine-modified cardo polyimidesPI-BPDA-BAFL(4Me)-Br(10.2%).

The analysis of the PI-BPDA-BAFL(4Me)-Br(10.2%) thus obtained gave thefollowing results.

[¹H-NMR analysis]

Ar—CH—Br₂ (δ: 6.3-6.6 ppm, br-m; integrated value, 0.00)

Ar—CH₂—Br (δ: 4.1-4.4 ppm, br-m; integrated value, 2.00)

Ar—CH₃ (δ: 1.8-2.4 ppm, br-m; integrated value, 6.81)

[Rate of modification by bromine] 10.2%

[Elemental analysis of Br] Br: 17.9%

[Number of bromine introduced to the benzyl position per repeating unit]Approximately 1.22

Membrane was made from the PI-BPDA-BAFL(4Me)-Br(10.2%) and gaspermeabilities of the membrane of the bromine-modified cardo polyimideswere as follows.

[Permeability coefficient of carbon dioxide]

1490×10⁻¹⁸m³.m/(m².s.Pa) (198 barrer)

[Permeability coefficient of nitrogen]

49.5×10⁻¹⁸m³.m/(m².s.Pa) (6.6 barrer)

[Carbon dioxide/nitrogen separation factor] 32

EXAMPLE 3

Using 26.5 g (40 millimoles) of the PI-BPDA-BAFL(4Me) prepared inExample 1 and 8.6 g (48 millimoles) of NBS, the bromination reaction,purification, and analysis were carried out as in Example 1.Approximately 3.6% of the 12 hydrogen atoms in the benzyl position inthe repeating unit, or approximately 0.43 hydrogen atom, was replaced bybromine atom to give bromine-modified cardo polyimidesPI-BPDA-BAFL(4Me)-Br(3.6%).

The analysis of the PI-BPDA-BAFL(4Me)-Br(3.6%) thus obtained gave thefollowing results.

[¹H-NMR analysis]

Ar—CH—Br₂ (δ: 6.3-6.6 ppm, br-m; integrated value, 0.00)

Ar—CH₂—Br (δ: 4.2-4.4 ppm, br-m; integrated value, 2.00)

Ar—CH₃ (δ: 1.8-2.3 ppm, br-m; integrated value, 24.78)

[Rate of modification by bromine] 3.6%

[Elemental analysis of Br] Br: 9.9%

[Number of bromine introduced to the benzyl position per repeating unit]Approximately 0.43

Membrane was made from the PI-BPDA-BAFL(4Me)-Br(3.6%) and gaspermeabilities of the membrane of the bromine-modified cardo polyimideswere as follows.

[Permeability coefficient of carbon dioxide]

2790×10⁻¹⁸m³.m/(m².s.Pa) (372 barrer)

[Permeability coefficient of nitrogen]

150×10⁻¹⁸m³.m/(m².s.Pa) (20 barrer)

[Carbon dioxide/nitrogen separation factor] 27

EXAMPLE 4

In 5,350 g of NMP were dissolved 521 g (1.28 moles) of9,9-bis(3′,5′-dimethyl-4′-aminophenyl)fluorene [BAFL(4Me)] and 567 g(1.28 moles) of2,2-bis(3′,4′-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride(6FDA) by stirring for 1 hour at room temperature and then the solutionwas kept at 180° C. and allowed to react for 26 hours with removal ofthe water being formed. Upon completion of the reaction, the reactionmixture was diluted by fresh addition of 5 liters of NMP, cooled, andpoured into 100 liters of methanol to give cardo polyimides as aprecipitate. The cardo polyimides thus obtained were washed twice with50 liters of methanol and dried under vacuum at 70° C. for 2 days and at100° C. for 1 day to give 960 g of cardo polyimides [PI-6FDA-BAFL(4Me);molecular weight of the repeating unit, 814.8] represented by thefollowing structural formula.

Using 32.7 g (40 millimoles) of the PI-6FDA-BAFL(4Me) thus prepared and51.3 g (288 millimoles) of NBS, the bromination reaction andpurification were carried out as in Example 1 to give bromine-modifiedPI-6FDA-BAFL(4Me).

The bromine-modified product thus obtained was analyzed as in Example 1to give the following results.

[¹H-NMR analysis]

Ar—OH—Br₂ (δ: 6.3-6.6 ppm, br-m; integrated value, 0.06)

Ar—CH₂—Br (δ: 4.1-4.4 ppm, br-m; integrated value, 2.00)

Ar—CH₃ (δ: 1.9-2.2 ppm, br-m; integrated value, 0.51)

[Rate of modification by bromine] 30.4%

[Elemental analysis of Br] Br: 31.9%

[Number of bromine introduced to the benzyl position per repeating unit]Approximately 3.64

As is apparent from these analytical results, the bromine-modifiedproduct is confirmed to be bromine-modified cardo polyimides[PI-6FDA-BAFL(4Me)-Br] represented by the following structural formula.

It is to be noted that there is the possibility of bromine atoms havingbeen introduced, although in small amounts, to the aromatic rings in therepeating unit.

As the aforementioned ¹H-NMR analysis of the bromine-modified productindicates, the intergrated values of the methylidyne proton in thebenzyl position after dibromination, the methylene protons in the benzylposition after monobromination, and the methyl protons in the tolylgroup in the absence of bromination are respectively 0.06, 2.00, and0.51 and this confirms that the bromine-modified product isPI-6FDA-BAFL(4Me)-Br(30.4%) formed by partial di- and mono-brominationof the side-chain methyl groups of the tolyl groups.

Membrane was made from the PI-6FDA-BAFL(4Me)-Br(30.4%) as in Example 1and gas permeabilities of the membrane of the bromine-modified cardopolyimides were as follows.

[Permeability coefficient of carbon dioxide]

1280×10⁻¹⁸m³.m/(m².s.Pa) (170 barrer)

[Permeability coefficient of nitrogen]

43.4×10⁻¹⁸m³.m/(m².s.Pa) (5.8 barrer)

[Carbon dioxide/nitrogen separation factor] 29

EXAMPLE 5

Using 32.7 g (40 millimoles) of the PI-6FDA-BAFL(4Me) prepared inExample 4 and 34.2 g (192 millimoles) of NBS, the bromination reaction,purification, and analysis were carried out as in Example 1.Approximately 18.1% of the 12 hydrogen atoms in the benzyl position, orapproximately 2.17 hydrogen atoms, was replaced by bromine atoms to givePI-6FDA-BAFL(4Me)-Br(18.1%).

The bromine-modified product thus obtained was analyzed as in Example 1to give the following results.

[¹H-NMR analysis]

Ar—CH—Br₂ (δ: 6.3-6.6 ppm, br-m; integrated value, 0.00)

Ar—CH₂—Br (δ: 4.2-4.4 ppm, br-m; integrated value, 2.00)

Ar—CH₃ (δ: 1.8-2.3 ppm, br-m; integrated value, 2.76)

[Rate of modification by bromine] 18.1%

[Elemental analysis of Br] Br: 24.0%

[Number of bromine introduced to the benzyl position per repeating unit]Approximately 2.17

Membrane was made from the PI-6FDA-BAFL(4Me)-Br(18.1%) and gaspermeabilities of the membrane of the bromine-modified cardo polyimideswere as follows.

[Permeability coefficient of carbon dioxide]

1800×10⁻¹⁸m³.m/(m².s.Pa) (240 barrer)

[Permeability coefficient of nitrogen]

68.3×10⁻¹⁸m³.m/(m².s.Pa) (9.1 barrer)

[Carbon dioxide/nitrogen separation factor] 26

EXAMPLE 6

Using 32.7 g (40 millimoles) of the PI-6FDA-BAFL(4Me) prepared inExample 4 and 17.1 g (96 millimoles) of NBS, the bromination reaction,purification, and analysis were carried out as in Example 1.Approximately 4.8% of the 12 hydrogen atoms in the benzyl position inthe repeating unit, or approximately 0.58 hydrogen atom, was replaced bybromine atoms to give PI-6FDA-BAFL(4Me)-Br(4.8%).

The analysis of the PI-6FDA-BAFL(4Me)-Br(4.8%) thus obtained gave thefollowing results.

[¹H-NMR analysis]

Ar—CH—Br₂ (δ: 6.3-6.6 ppm, br-m; integrated value, 0.00)

Ar—CH₂—Br (δ: 4.1-4.4 ppm, br-m; integrated value, 2.00)

Ar—CH₃ (δ: 1.9-2.2 ppm, br-m; integrated value, 17.71)

[Rate of modification by bromine] 4.8%

[Elemental analysis of Br] Br: 9.4%

[Number of bromine introduced to the benzyl position per repeatingunit]. Approximately 0.58.

Membrane was made from the PI-6FDA-BAFL(4Me)-Br(4.8%) and gaspermeabilities of the membrane of the bromine-modified cardo polyimideswere as follows.

[Permeability coefficient of carbon dioxide]

4060×10⁻¹⁸m³.m/(m².s.Pa) (541 barrer)

[Permeability coefficient of nitrogen]

198×10⁻¹⁸m³.m/(m².s.Pa) (26.4 barrer)

[Carbon dioxide/nitrogen separation factor] 21

EXAMPLE 7

In 5,000 g of NMP were dissolved 650 g (1.59 moles) of9,9-bis(3′,5′-dimethyl-4′-aminophenyl)fluorene [BAFL(4Me)], 188 g (0.64mole) of 3,3′,4,4′-biphenyltetracarboxylic acid dianhydride (BPDA), and209 g (0.96 mole) of pyromellitic dianhydride (PMDA) by stirring for 1hour at room temperature and then the solution was kept at 180° C. andallowed to react for 8 hours with removal of the water being formed.Upon completion of the reaction, the reaction mixture was diluted byfresh addition of 18 liters of NMP, cooled, and poured into 160 litersof methanol to give cardo polyimides as a precipitate. The cardopolyimides thus obtained were washed twice with 50 liters of methanoland dried under vacuum at 70° C. for 2 days and at 100° C. for 1 day togive 950 g of cardo polyimides [PI-PMBP64-BAFL(4Me); molecular weight ofthe repeating unit, 618.3] represented by the following structuralformula.

Using 24.7 g (40 millimoles) of the PI-PMBP64-BAFL(4Me) and 51.3 g (288millimoles) of N-bromosuccinimide (NBS), the bromination reaction andpurification were carried out as in Example 1 to give bromine-modifiedPI-PMBP64-BAFL(4Me).

The analysis made in the same manner as in Example 1 on thebromine-modified product gave the following results.

[¹H-NMR analysis]

Ar—CH—Br₂ (δ: 6.3-6.6 ppm, br-m; integrated value, 0.04)

Ar—CH₂—Br (δ: 4.1-4.5 ppm, br-m; integrated value, 2.00)

Ar—CH₃ (δ: 1.9-2.2 ppm, br-m; integrated value, 0.61)

[Rate of modification by bromine] 29.0%

[Elemental analysis of Br] Br: 34.7%

[Number of bromine introduced to the benzyl position per repeating unit]Approximately 3.47

As is apparent from these analytical results, the bromine-modifiedproduct thus obtained was confirmed to be bromine-modified cardopolyimides [PI-PMBP64-BAFL(4Me)-Br] represented by the followingstructural formula.

As the results of ¹H-NMR analysis indicate, the integrated values of themethylene protons in the benzyl position after monobromination and themethyl protons in the tolyl group in the absence of bromination arerespectively 2.00 and 0.61 and this confirms that the product isPI-PMBP64-BAFL(4Me)-Br(29.0%) resulting from partial di- andmono-bromination of the side-chain methyl groups.

Membrane was made from 5 g of the PI-PMBP64-BAFL(4Me)-Br(29.0%) as inExample 1 and gas permeabilities of the membrane of the bromine-modifiedcardo polyimides were as follows.

[Permeability coefficient of carbon dioxide]

1058×10⁻¹⁸m³.m/(m².s.Pa) (141 barrer)

[Permeability coefficient of nitrogen]

30.8×10⁻¹⁸m³.m/(m².s.Pa) (4.1 barrer)

[Carbon dioxide/nitrogen separation factor] 34

EXAMPLE 8

Using 24.7 g (40 millimoles) of the PI-PMBP64-BAFL(4Me) prepared inExample 7 and 34.2 g (192 millimoles) of NBS, the bromination reaction,purification, and analysis were carried out as in Example 1.Approximately 22.1% of the 12 hydrogen atoms in the benzyl position inthe BAFL(4Me) segment, or approximately 2.82 hydrogen atoms, wasreplaced by bromine atoms to give bromine-modified cardo polyimides[PI-PMBP64-BAFL(4Me)-Br(22.1%)].

The analysis made in the same manner as in Example 1 on thebromine-modified product gave the following results.

[¹H-NMR analysis]

Ar—CH—Br₂ (δ: 6.3-6.6 ppm, br-m; integrated value, 0.00)

Ar—CH₂—Br (δ: 4.1-4.5 ppm, br-m; integrated value, 2.00)

Ar—CH₃ (δ: 1.9-2.2 ppm, br-m; integrated value, 1.58)

[Rate of modification by bromine] 22.1%

[Elemental analysis of Br] Br: 29.4%

[Number of bromine introduced to the benzyl position per repeating unit]Approximately 2.66

Membrane was made from the PI-PMBP64-BAFL(4Me)-Br(22.1%) and gaspermeabilities of the membrane of the bromine-modified cardo polyimideswere as follows.

[Permeability coefficient of carbon dioxide]

1300×10⁻¹⁸m³.m/(m².s.Pa) (173 barrer)

[Permeability coefficient of nitrogen]

38.3×10⁻¹⁸m³.m/(m².s.Pa) (5.1 barrer)

[Carbon dioxide/nitrogen separation factor] 33

EXAMPLE 9

Using 24.7 g (40 millimoles) of the PI-PMBP64-BAFL(4Me) prepared inExample 7 and 17.1 g (96 millimoles) of NBS, the bromination reaction,purification, and analysis were carried out as in Example 1.Approximately 7.3% of the 12 hydrogen atoms in the benzyl position inthe BAFL(4Me) segment, or approximately 0.88 hydrogen atom, was replacedby bromine atoms to give PI-PMBP64-BAFL(4Me)-Br(7.3%).

[¹H-NMR analysis]

Ar—CH—Br₂ (δ: 6.3-6.6 ppm, br-m; integrated value, 0.00)

Ar—CH₂—Br (δ: 4.1-4.4 ppm, br-m; integrated value, 2.20)

Ar—CH₃ (δ: 1.9-2.2 ppm, br-m; integrated value, 11.73)

[Rate of modification by bromine] 7.3%

[Elemental analysis of Br] Br: 12.8%

[Number of bromine introduced to the benzyl position per repeatingunit]. Approximately 0.88.

Membrane was made from the PI-PMBP64-BAFL(4Me)-Br(7.3%)and gaspermeabilities of the membrane of the bromine-modified cardo polyimideswere as follows.

[Permeability coefficient of carbon dioxide]

4720×10⁻¹⁸m³.m/(m².s.Pa) (629 barrer)

[Permeability coefficient of nitrogen]

185×10⁻¹⁸m³.m/(m².s.Pa) (24.6 barrer)

[Carbon dioxide/nitrogen separation factor] 26

EXAMPLE 10

Using 24.7 g (40 millimoles) of the PI-PMBP64-BAFL(4Me) prepared inExample 7 and 8.6 g (48 millimoles) of NBS, the bromination reaction,purification, and analysis were carried out as in Example 1.Approximately 2.4% of the 12 hydrogen atoms in the benzyl position inthe BAFL(4Me) segment, or approximately 0.29 hydrogen atom, was replacedby bromine atoms to give PI-PMBP64-BAFL(4Me)-Br(2.4%).

[¹H-NMR analysis]

Ar—CH—Br₂ (δ: 6.3-6.6 ppm, br-m; integrated value, 0.00)

Ar—CH₂—Br (δ: 4.1-4.4 ppm, br-m; integrated value, 0.75)

Ar—CH₃ (δ: 1.9-2.2 ppm, br-m; integrated value, 14.39)

[Rate of modification by bromine] 2.4%

[Elemental analysis of Br] Br: 6.0%

[Number of bromine introduced to the benzyl position per repeating-unit]Approximately 0.29

Membrane was made from the PI-PMBP64-BAFL(4Me)-Br(2.4%) and gaspermeabilities of the membrane of the bromine-modified cardo polyimideswere as follows.

[Permeability coefficient of carbon dioxide]

6680×10⁻¹⁸m³.m/(m².s.Pa) (891 barrer)

[Permeability coefficient of nitrogen]

293×10⁻¹⁸m³.m/(m².s.Pa) (39.1 barrer)

[Carbon dioxide/nitrogen separation factor] 23

EXAMPLE 11 Amination with Diethanolamine

In 50 ml of NMP was dissolved 2.78 g of thePI-PMBP64-BAFL(4Me)-Br(7.3%)(4 millimoles; molecular weight of repeatingunit, 695.1) prepared in Example 9 at room temperature, 1.01 g (9.6millimoles) of diethanolamine was added, and the reaction was allowed toproceed for 3 hours. The reaction mixture was poured into 600 ml ofdistilled water to give polymers as a precipitate. The precipitate wascollected, washed with grinding in a mixer by fresh addition of 400 mlof methanol, and further washed 4 times with 400 ml of methanol.Thereafter, the precipitate was dried under vacuum at 30° C. for 12hours to give diethanolamine-modified polymers.

The IR analysis of the ethanolamine-modified polymers showed anabsorption band characteristic of diethanolamine at 2800˜3000 cm⁻¹ andconfirmed that the bromine atoms in the PI-PMBP64-BAFL(4Me)-Br(7.3%)were partly replaced by diethanolamine to give diethanolamine-modifiedcardo polyimides.

The diethanolamine-modified cardo polyimides were dissolved in NMP andmade into membrane as in Example 1. Gas permeabilities of the membraneof the diethanolamine-modified cardo polyimides were as follows.

[Permeability coefficient of carbon dioxide]

245×10⁻¹⁸m³.m/(m².s.Pa) (32.6 barrer)

[Permeability coefficient of nitrogen]

5.25×10⁻¹⁸m³.m/(m².s.Pa) (0.7 barrer)

[Carbon dioxide/nitrogen separation factor] 44

EXAMPLE 12 Amination with Diethylamine

The procedure of Example 11 was followed to preparediethylamine-modified polymers by using 0.70 g (9.6 millimoles) ofdiethylamine in place of diethanolamine.

The IR analysis of the diethylamine-modified polymers showed anabsorption band characteristic of diethylamine at 2800˜3000 cm⁻¹ andconfirmed that the bromine atoms in the PI-PMBP64-BAFL(4Me)-Br(7.3%)were partly replaced by diethylamine to give diethylamine-modified cardopolyimides.

Gas permeabilities of the membrane made as in Example 1 from thediethylamine-modified cardo polyimides were as follows.

[Permeability coefficient of carbon dioxide]

360×10⁻¹⁸m³.m/(m².s.Pa) (48.0 barrer)

[Permeability coefficient of nitrogen]

9×10⁻¹⁸m³.m/(m².s.Pa) (1.2 barrer)

[Carbon dioxide/nitrogen separation factor] 40

EXAMPLE 13 Amination with Morpholine

The procedure of Example 11 was followed to prepare morpholine-modifiedpolymers by using 0.70 g (8.0 millimoles) of morpholine in place ofdiethanolamine.

The IR analysis of the morpholine-modified polymers showed an absorptionband characteristic of morpholine at 2800˜3000 cm⁻¹ and confirmed thatthe bromine atoms in the PI-PMBP64-BAFL(4Me)-Br(7.3%) were partlyreplaced by morpholine to give morpholine-modified cardo polyimides.

Gas permeabilities of the membrane made as in Example 1 from themorpholine-modified cardo polyimides were as follows.

[Permeability coefficient of carbon dioxide]

505×10⁻¹⁸m³.m/(m².s.Pa) (67.3 barrer)

[Permeability coefficient of nitrogen]

13×10⁻¹⁸m³.m/(m².s.Pa) (1.7 barrer)

[Carbon dioxide/nitrogen separation factor] 39

EXAMPLE 14 Hydroxylation

In 80 ml of NMP was dissolved 2.78 g (4 millimoles) of thePI-PMBP64-BAFL(4Me)-Br(7.3%) prepared in Example 9, 10.4 g of 40%aqueous solution of tetra-n-butylammonium hydroxide (equivalent to 16millimoles) was added, and the reaction was allowed to proceed at roomtemperature for 10 hours with vigorous stirring. The reaction mixturewas poured into 1000 ml of distilled water to separate polymers as aprecipitate. The precipitate was collected, washed with grinding in amixer with fresh addition of 500 ml of distilled water, and furtherwashed three times with 500 ml of distilled water and three times with400 ml of methanol. Thereafter, the precipitate was dried under vacuumat 50° C. for 12 hours to give a hydroxyl-modified product.

The IR analysis of the hydroxyl-modified product showed an absorptionband characteristic of the hydroxyl group at 3200˜3600 cm⁻¹ andconfirmed that the bromine atoms in the PI-PMBP64-BAFL(4Me)-Br(7.3%)were partly replaced by hydroxyl groups to give hydroxyl-modified cardopolyimides.

The hydroxyl-modified cardo-type polyimides were dissolved in NMP andmade into membrane as in Example 1. Gas permeabilities of the membraneof the hydroxyl-modified cardo polyimides were as follows.

[Permeability coefficient of carbon dioxide]

263×10⁻¹⁸m³.m/(m².s.Pa) (35.1 barrer)

[Permeability coefficient of nitrogen]

7×10⁻¹⁸m³.m/(m².s.Pa) (0.9 barrer)

[Carbon dioxide/nitrogen separation factor] 39

EXAMPLE 15 Hydroxylation

In 80 ml of dichloromethane was dissolved 2.78 g (4 millimoles) of thePI-PMBP64-BAFL(4Me)-Br(7.3%) prepared in Example 9 at room temperature,2.2 g (40.0 millimoles) of pulverized potassium hydroxide and 0.12 g(0.4 millimole) of tetra-n-butylammonium chloride were added, and thereaction was allowed to proceed at room temperature for 10 hours withvigorous stirring. The reaction mixture was poured into 1000 ml ofdistilled water to separate polymers as a precipitate. The precipitatewas collected, washed with grinding in a mixer with fresh addition of500 ml of distilled water, and further washed five times with 500 ml ofdistilled water and three times with 400 ml of methanol. Thereafter, theprecipitate was dried under vacuum at 50° C. for 12 hours to give ahydroxyl-modified product.

The IR analysis of the hydroxyl-modified product showed an absorptionband characteristic of the hydroxyl group at 3200˜3600 cm⁻¹ andconfirmed that the bromine atoms in the PI-PMBP64-BAFL(4Me)-Br(7.3%)were partly replaced by hydroxyl groups to give hydroxyl-modified cardopolyimides.

The hydroxyl-modified cardo polyimides were dissolved in NMP and madeinto membrane as in Example 1. Gas permeabilities of the membrane of thehydroxyl-modified cardo polyimides were as follows.

[Permeability coefficient of carbon dioxide]

302×10⁻¹⁸m³.m/(m².s.Pa) (40.2 barrer)

[Permeability coefficient of nitrogen]

7.5×10⁻¹⁸m³.m/(m².s.Pa) (1.0 barrer)

[Carbon dioxide/nitrogen separation factor] 41

EXAMPLE 16 Methylthiolation

In 80 ml of tetrahydrofuran was dissolved 2.78 g (4 millimoles) of thePI-PMBP64-BAFL(4Me)-Br(7.3%) prepared in Example 9 at room temperature,0.56 g (8.0 millimoles) of sodium methanethioxide and 0.12 g (0.4millimole) of tetra-n-butylammonium chloride were added, and thereaction was allowed to proceed at room temperature for 5 hours withvigorous stirring. The reaction mixture was processed as in Example 14to give a methylthio-modified product.

The difference spectrum in the IR analysis of the methylthio-modifiedproduct showed an absorption band characteristic of the mercapto groupin the vicinity of 2570 cm⁻¹ and confirmed that the bromine atoms in thePI-PMBP64-BAFL(4Me)-Br(7.3%) were partly replaced by methylthio groupsto give methylthio-modified cardo polyimides.

The methylthio-modified cardo polyimides were dissolved in NMP and madeinto membrane as in Example 1. Gas permeabilities of the membrane of themethylthio-modified cardo polyimides were as follows.

[Permeability coefficient of carbon dioxide]

590×10⁻¹⁸m³.m/(m².s.Pa) (78.6 barrer)

[Permeability coefficient of nitrogen]

16×10⁻¹⁸m³.m/(m².s.Pa) (2.1 barrer)

[Carbon dioxide/nitrogen separation factor] 38

EXAMPLE 17 Substitution by Thiomorpholine

In 50 ml of NMP was dissolved 2.78 g (4 millimoles) of thePI-PMBP64-BAFL(4Me)-Br(7.3%) prepared in Example 9 at room temperature,0.50 g (4.8 millimoles) of thiomorpholine and 0.97 g (9.6 millimoles) oftriethylamine were added, and the reaction was allowed to proceed atroom temperature for 3 hours. The reaction mixture was processed as inExample 11 to give a thiomorpholino-modified product.

The IR analysis of the thiomorpholine-modified product showed anabsorption band characteristic of thiomorpholine at 2800˜3000 cm⁻¹ andconfirmed that the bromine atoms in the PI-PMBP64-BAFL(4Me)-Br(7.3%)were partly replaced by thiomorpholino groups to givethiomorpholino-modified cardo polyimides.

The thiomorpholino-modified cardo polyimides were dissolved in NMP andmade into membrane as in Example 1. Gas permeabilities of the membraneof the thiomorpholino-modified cardo polyimides were as follows.

[Permeability coefficient of carbon dioxide]

780×10⁻¹⁸m³.m/(m².s.Pa) (104 barrer)

[Permeability coefficient of nitrogen]

22×10⁻¹⁸m³.m/(m².s.Pa) (2.9 barrer)

[Carbon dioxide/nitrogen separation factor] 36

EXAMPLE 18 Acetoxylation

In 50 ml of dimethyl sulfoxide (DMSO) was dissolved 2.78 g (4millimoles) of the PI-PMBP64-BAFL(4Me)-Br(7.3%) prepared in Example 9 atroom temperature, 0.47 g (4.8 millimoles) of potassium acetate andN,N,N′,N′-tetramethylethylenediamine were added, and the reaction wasallowed to proceed at room temperature for 1 hour. The reaction mixturewas processed as in Example 11 to give an acetyloxy-modified product.

The difference spectrum in the IR analysis of the acetyloxy-modifiedproduct showed an absorption band assignable to the carbonyl group ofthe acetyloxy group in the vicinity of 1745 cm⁻¹ and confirmed that thebromine atoms in the PI-PMBP64-BAFL(4Me)-Br(7.3%) were partly replacedby acetyloxy groups to give acetyloxy-modified cardo polyimides.

The thiomorpholino-modified cardo polyimides were dissolved in NMP andmade into membrane as in Example 1. Gas permeabilities of the membraneof the acetyloxy-modified cardo polyimides were as follows.

[Permeability coefficient of carbon dioxide]

601×10⁻¹⁸m³.m/(m².s.Pa) (80.1 barrer)

[Permeability coefficient of nitrogen]

17×10⁻¹⁸m³.m/(m².s.Pa) (2.2 barrer)

[Carbon dioxide/nitrogen separation factor] 37

EXAMPLE 19 Cyanation

In 80 ml of dichloromethane was dissolved 2.78 g (4 millimoles) of thePI-PMBP64-BAFL(4Me)-Br(7.3%) prepared in Example 9 at room temperature,1.25 g (8.0 millimoles) of tetraethylammonium cyanide andtetramethyleneethylenediamine were added, and the reaction was allowedto proceed at room temperature for 5 hours. The reaction mixture wasprocessed as in Example 11 to give a cyano-modified product.

The difference spectrum in the IR analysis of the cyano-modified productshowed an absorption band characteristic of the cyano group in thevicinity of 2245 cm⁻¹ and confirmed that the bromine atoms in thePI-PMBP64-BAFL(4Me)-Br(7.3%) were partly replaced by cyano groups togive cyano-modified cardo polyimides.

The cyano-modified cardo polyimides were dissolved in NMP and made intomembrane as in Example 1. Gas permeabilities of the membrane of thecyano-modified cardo polyimides were as follows.

[Permeability coefficient of carbon dioxide]

618×10⁻¹⁸m³.m/(m².s.Pa) (82.4barrer)

[Permeability coefficient of nitrogen]

18×10⁻¹⁸m³.m/(m².s.Pa) (2.4barrer)

[Carbon dioxide/nitrogen separation factor] 35

EXAMPLE 20 Sulfonation

In 80 ml of dichloromethane was dissolved 2.78 g (4 millimoles) of thePI-PMBP64-BAFL(4Me)-Br(7.3%) prepared in Example 9 at room temperature,2.41 g (8.0 millimoles) of tetraethylammonium p-toluenesulfonate wasadded, and the reaction was allowed to proceed at room temperature for 5hours. The reaction mixture was processed as in Example 11 to give asulfonyl-modified product.

The difference spectrum in the IR analysis of the sulfonyl-modifiedproduct showed absorption bands characteristic of the sulfonyl group inthe vicinity of 1350 cm⁻¹ and 1175 cm⁻¹ and confirmed that the bromineatoms in the PI-PMBP64-BAFL(4Me)-Br(7.3%) were partly replaced bytoluenesulfonyl groups to give sulfonyl-modified cardo polyimides.

The sulfonyl-modified cardo polyimides were dissolved in NMP and madeinto membrane as in Example 1. Gas permeabilities of the membrane of thesulfonyl-modified cardo polyimides were as follows.

[Permeability coefficient of carbon dioxide]

241×10⁻¹⁸m³.m/(m².s.Pa) (32.1 barrer)

[Permeability coefficient of nitrogen]

6×10⁻¹⁸m³.m/(m².s.Pa) (0.8 barrer)

[Carbon dioxide/nitrogen separation factor] 40

EXAMPLE 21 Nitration

In 80 ml of tetrahydrofuran was dissolved 2.78 g (4 millimoles) of thePI-PMBP64-BAFL(4Me)-Br(7.3%) prepared in Example 9 at room temperature,8.79 g of 35% aqueous solution of tetraethylammonium nitrate (equivalentto 16.0 millimoles) was added, and the reaction was allowed to proceedat room temperature for 10 hours with vigorous stirring. The reactionmixture was poured into 1000 ml of distilled water to separate polymersas a precipitate. The precipitate was collected, washed with grinding ina mixer with fresh addition of 500 ml of distilled water, and furtherwashed three times with 500 ml of distilled water and three times with400 ml of methanol. Thereafter, the precipitate was dried under vacuumat 50° C. for 12 hours to give a nitro-modified product.

The difference spectrum in the IR analysis of the nitro-modified productshowed an absorption band characteristic of the nitro group in thevicinity of 1600 cm⁻¹ and confirmed that the bromine atoms in thePI-PMBP64-BAFL(4Me)-Br(7.3%) were partly replaced by nitro groups togive nitro-modified cardo polyimides.

The nitro-modified cardo polyimides were dissolved in NMP and made intomembrane as in Example 1. Gas permeabilities of the membrane of thenitro-modified cardo polyimides were as follows.

[Permeability coefficient of carbon dioxide]

410×10⁻¹⁸m³.m/(m².s.Pa) (54.7 barrer)

[Permeability coefficient of nitrogen]

11×10⁻¹⁸m³.m/(m².s.Pa) (1.5 barrer)

[Carbon dioxide/nitrogen separation factor] 37

EXAMPLE 22 Synthesis of PI-BTDA-BAFL(4Me)

In 4130 g of N-methyl-2-pyrrolidone (NMP) were dissolved 489.6 g (1.20moles) of 9,9-bis(3′,5′-dimethyl-4′-aminophenyl)fluorene [BAFL(4Me)] and386.3 g (1.20 moles) of 3,3′,4,4′-benzophenonetetracarboxylic aciddianhydride (BTDA) at room temperature with stirring for 1 hour, thenthe solution was kept at 180° C. and allowed to react for 8 hours withremoval of the water being formed. Upon completion of the reaction, thereaction mixture was diluted with fresh addition of 14 liters of NMP,cooled, and poured into 150 liters of methanol to separate polymers as aprecipitate. The precipitate was ground, washed twice with 50 liters ofmethanol, and dried under vacuum at 70° C. for 2 days and at 100° C. for1 day to give 830 g of cardo polyimides [PI-BTDA-BAFL(4Me); molecularweight of repeating unit, 690.2] represented by the following structuralformula.

Using 27.5 g (40 millimoles) of the PI-BTDA-BAFL(4Me) and 51.3 g (288millimoles) of NBS, the reaction for modification by bromine andpurification were carried out as in Example 1 to give bromine-modifiedPI-BTDA-BAFL(4Me)-Br.

The structural analysis made on the bromine-modified product as inExample 1 confirmed that the product is bromine-modified cardopolyimides [PI-BTDA-BAFL(4Me)-Br] represented by the followingstructural formula. It is to be noted that there is the possibility ofbromine atoms, although in small amounts, having been introduced to thearomatic rings in the repeating unit.

As the ¹H-NMR analysis indicates, the intergrated values of themethylidyne proton in the benzyl position after dibromination, themethylene protons in the benzyl position after monobromination, and themethyl protons in the tolyl group in the absence of bromination arerespectively 0.08, 6.00, and 1.82 and this confirms that thebromine-modified product is PI-BTDA-BAFL(4Me)-Br(28.6%) formed bypartial di- and monobromination of the methyl groups in the tolylgroups.

[¹H-NMR analysis]

Ar—CH—Br₂ (δ: 6.3-6.6 ppm, br-m; integrated value, 0.08)

Ar—CH₂—Br (δ: 4.2-4.4 ppm, br-m; integrated value, 6.00)

Ar—CH₃ (δ: 2.0-2.2 ppm, br-m; integrated value, 1.82)

[Rate of modification by bromine] 28.6%

[Elemental analysis of Br] Br: 32.9%

[Number of bromine introduced to the benzyl position per repeating unit]Approximately 3.43

Membrane was made from 5 g of the PI-BTDA-BAFL(4Me)-Br(28.6%) as inExample 1 and gas permeabilities of the membrane of the bromine-modifiedcardo polyimides were as follows.

[Permeability coefficient of carbon dioxide]

391×10⁻¹⁸m³.m(m².s.Pa) (52.1 barrer)

[Permeability coefficient of nitrogen]

9.8×10⁻¹⁸m³.m/(m².s.Pa) (1.3 barrer)

[Carbon dioxide/nitrogen separation factor] 39

EXAMPLE 23

Using 27.5 g (40 millimoles) of the PI-BTDA-BAFL(4Me) prepared inExample 22 and 28.5 g (160 millimoles) of NBS, the reaction formodification by bromine, purification, and analysis were carried out asin Example 1. Approximately 15.6% of the 12 hydrogen atoms in the benzylposition was replaced by bromine atoms to givePI-BTDA-BAFL(4Me)-Br(15.6%).

[¹H-NMR analysis]

Ar—CH—Br₂ (δ: 6.4-6.6 ppm, br-m; integrated value, 0.00)

Ar—CH₂—Br (δ: 4.1-4.4 ppm, br-m; integrated value, 4.00)

Ar—CH₃ (δ: 1.8-2.4 ppm, br-m; integrated value, 6.81)

[Rate of modification by bromine] 15.6%

[Elemental analysis of Br] Br: 21.4%

[Number of bromine introduced to the benzyl position per repeating unit]Approximately 1.87

Membrane was made from the PI-BTDA-BAFL(4Me)-Br(15.6%) and gaspermeabilities of the membrane of the bromine-modified cardo polyimideswere as follows.

[Permeability coefficient of carbon dioxide]

788×10⁻¹⁸m³.m/(m².s.Pa) (105 barrer)

[Permeability coefficient of nitrogen]

2×10⁻¹⁸m³.m/(m².s.Pa) (0.3 barrer)

[Carbon dioxide/nitrogen separation factor] 35

EXAMPLE 24 Excessive Bromination of PI-BPDA-BAFL(4Me)

In 500 ml of 1,2-dichloroethane was dissolved 13.3 g (20 millimoles) ofthe PI-BPDA-BAFL(4Me) prepared in Example 1 at room temperature with onehour stirring, 51.3 g (288 millimoles) of NBS and 1.0 g of AIBN wereadded, and the reaction was allowed to proceed under reflux condition(the temperature of solution being approximately 90-100° C.) for 24hours. Upon completion of the reaction, the reaction mixture was pouredinto 4.5 liters of methanol to separate polymers as a precipitate. Theprecipitate was collected, washed with grinding in a mixer with freshaddition of 1 liter of methanol, and further washed with methanol untilthe filtrate became colorless and transparent. Thereafter, theprecipitate was dried under vacuum at 50° C. for 12 hours. Analysis inthe same way as Example 1 shows that approximately 36.3% of the 12hydrogen atoms in the benzyl position was replaced by bromine atoms togive PI-BPDA-BAFL(4Me)-Br(36.3%).

[¹H-NMR analysis]

Ar—CH—Br² (δ: 6.4-6.6 ppm, br-m; integrated value, 0.14)

Ar—CH²—Br (δ: 4.1-4.4 ppm, br-m; integrated value, 2.00)

Ar—CH³ (δ: 1.9-2.2 ppm, br-m; integrated value, 0.11)

[Rate of modification by bromine] 36.3%

[Elemental analysis of Br] Br: 38.8%

[Number of bromine introduced to the benzyl position per repeating unit]Approximately 4.35

Membrane was made from the PI-BPDA-BAFL(4Me)-Br(36.3%) and gaspermeabilities of the membrane of the bromine-modified cardo polyimideswere as follows.

[Permeability coefficient of carbon dioxide]

576×10⁻¹⁸m³.m/(m².s.Pa) (76.8 barrer)

[Permeability coefficient of nitrogen]

16×10⁻¹⁸m³.m/(m².s.Pa) (2.1 barrer)

[Carbon dioxide/nitrogen separation factor] 37

EXAMPLE 25 Excessive Bromination of PI-6FDA-BAFL(4Me)

Using 16.2 g (20 millimoles) of the PI-6FDA-BAFL(4Me) prepared inExample 4 and 51.3 g (288 millimoles) of NBS, the reaction formodification by bromine, purification, and analysis were carried out asin Example 24. Approximately 36.8% of the 12 hydrogen atoms in thebenzyl position was brominated to give PI-6FDA-BAFL(4Me)-Br(36.8%).

[¹H-NMR analysis]

Ar—CH—Br₂ (δ: 6.4-6.6 ppm, br-m; integrated value, 0.16)

Ar—CH₂—Br (δ: 4.1-4.4 ppm, br-m; integrated value, 2.00)

Ar—CH₃ (δ: 1.9-2.2 ppm, br-m; integrated value, 0.11)

[Rate of modification by bromine] 36.8%

[Elemental analysis of Br] Br: 35.8%

[Number of bromine introduced to the benzyl position per repeating unit]Approximately 4.41

Membrane was made from the PI-6FDA-BAFL(4Me)-Br(36.8%) as in Example 1and gas permeabilities of the membane of the bromine-modified cardopolyimides were as follows.

[Permeability coefficient of carbon dioxide]

930×10⁻¹⁸m³.m/(m².s.Pa) (124 barrer)

[Permeability coefficient of nitrogen]

29×10⁻¹⁸m³.m/(m².s.Pa) (3.9 barrer)

[Carbon dioxide/nitrogen separation factor] 32

EXAMPLE 26 Excessive Bromination of PI-BTDA-BAFL(4Me)

Using 13.8 g (20 millimoles) of the PI-BTDA-BAFL(4Me) prepared inExample 22 and 51.3 g (288 millimoles) of NBS, the reaction formodification by bromine, purification, and analysis were carried out asin Example 24. Approximately 35.6% of the 12 hydrogen atoms in thebenzyl position was brominated to give PI-BTDA-BAFL(4Me)-Br(35.6%).

[¹H-NMR analysis]

Ar—CH—Br₂ (δ: 6.4-6.6 ppm, br-m; integrated value, 0.11)

Ar—CH₂—Br (δ: 4.1-4.4 ppm, br-m; integrated value, 2.00)

Ar—CH₃ (δ: 1.9-2.2 ppm, br-m; integrated value, 0.10)

[Rate of modification by bromine] 35.6%

[Elemental analysis of Br] Br: 35.5%

[Number of bromine introduced to the benzyl position per repeating unit]Approximately 4.27

Membrane was made from the PI-BTDA-BAFL(4Me)-Br(35.6%) as in Example 1and gas permeabilities of the membrane of the bromine-modified cardopolyimides were as follows.

[Permeability coefficient of carbon dioxide]

215×10⁻¹⁸m³.m/(m².s.Pa) (28.7 barrer)

[Permeability coefficient of nitrogen]

5×10⁻¹⁸m³.m/(m².s.Pa) (0.7 barrer)

[Carbon dioxide/nitrogen separation factor] 40

EXAMPLE 27 Temperature for Elimination of Bromine

In order to examine the heat stability of bromine-modified cardopolyimides and the temperature at which bromine is eliminated, theseproperties were determined with the use of TG (thermogravimetry)-GC/MSmethod (TG-MS method and trap GC/MS method). The TG-MS(thermo(gravimetry-mass spectrometry) method uses a device in which athermogravimetric instrument is directly connected to a massspectrometer and determines the change in weight of the specimen andsimultaneously keeps track of gases generated from the specimen duringheating while recording the change in concentration for each mass numberas a function of temperature. On the other hand, the trap GC/MS (gaschromatography/mass spectrometry) method traps a part of the gasesgenerated inside the thermogravimetric instrument by an absorbent,reheats the absorbent, and analyzes the generated gases by GC/MS.

Specimens: PI-PMBP64-BAFL(4Me)-Br(29.0%), PI-BPDA-BAFL(4Me)-Br(27.6%),and PI-6FDA-BAFL(4Me)-Br(30.3%), all in powder

Conditions for measurement:

Apparatus; TG-MS, devices working simultaneously

Atmosphere; stream of helium (30 ml/min)

Temperature range; room temperature→1000° C.

Heat-up speed; 20° C./min

Condition for thermal elimination; temperature 280° C., absorbent C300

As a results, it was observed for each specimen that the generation ofHBr started in the vicinity of 300° C. and reached a peak in thevicinity of 440° C.

EXAMPLE 28 Synthesis of PI-BPDA-BAFL(4Me)-Cl

Using 26.5 g (40 millimoles) of the PI-BPDA-BAFL(4Me) prepared inExample 1 and 38.5 g (288 millimoles) of N-chlorosuccinimide (NCS), thereaction for modification by chlorine, purification, and analysis werecarried out as in Example 1. Approximately 7.7% of the 12 hydrogen atomsin the benzyl position was chlorinated to givePI-BPDA-BAFL(4Me)-Cl(7.7%).

[¹H-NMR analysis]

Ar—CH₂—Cl (δ: 4.3-4.5 ppm, br-m; integrated value, 2.00)

Ar—CH₃ (δ: 1.9-2.2 ppm, br-m; integrated value, 10.01)

[Rate of modification by chlorine] 7.7%

[Elemental analysis of Cl] Cl: 5.0%

[Number of chlorine introduced to the benzyl position per repeatingunit]. Approximately 0.92.

Membrane was made from the PI-BPDA-BAFL(4Me)-Cl(7.7%) and gaspermeabilities of the members of the chlorine-modified cardo polyimideswere as follows.

[Permeability coefficient of carbon dioxide]

4140×10⁻¹⁸m³.m/(m².s.Pa) (552 barrer)

[Permeability coefficient of nitrogen]

148×10⁻¹⁸m³.m/(m².s.Pa) (19.7 barrer)

[Carbon dioxide/nitrogen separation factor] 28

EXAMPLE 29 Synthesis of PI-PMBP64-BAFl(4Me)-Cl

Using 24.7 g (40 millimoles) of the PI-PMBP64-BAFL(4Me) prepared inExample 7 and 38.5 g (288 millimoles) of NCS, the reaction formodification by chlorine, purification, and analysis were carried out asin Example 27. Approximately 7.0% of the 12 hydrogen atoms in the benzylposition was chlorinated to give PI-PMBP64-BAFL(4Me)-Cl(7.0%).

[¹H-NMR analysis]

Ar—CH₂—Cl (δ: 4.3-4.5 ppm, br-m; integrated value, 2.00)

Ar—CH₃ (δ: 1.9-2.2 ppm, br-m; integrated value, 11.26)

[Rate of modification by chlorine] 7.0%

[Elemental analysis of Cl] Cl: 4.8%

[Number of bromine introduced to the benzyl position per repeatingunit]. Approximately 0.84.

Membrane was made from the PI-PMBP64-BAFL(4Me)-Cl (7.0%) and gaspermeabilities of the membrane of the chlorine-modified cardo polyimideswere as follows.

[Permeability coefficient of carbon dioxide]

5570×10⁻¹⁸m³.m/(m².s.Pa) (743 barrer)

[Permeability coefficient of nitrogen]

215×10⁻¹⁸m³.m/(m².s.Pa) (28.6 barrer)

[Carbon dioxide/nitrogen separation factor] 26

EXAMPLE 30 Synthesis of PI-BPDA-BAFL(4Et)-Br

Using 9,9-bis(3′,5′-diethyl-4-aminophenyl)fluorene [BAFL(4Et)] and BPDA,the polymerization was carried out as in Example 1 to givePI-BPDA-BAFL(4Et) represented by the following structural formula.

Using the PI-BPDA-BAFL(4Et) thus obtained and NBS, the reaction formodification by bromine, purification, and analysis were carried out asin Example 1. Several % of the 12 hydrogen atoms in the benzyl positionwas brominated to give PI-BPDA-BAFL(4Et)-Br represented by the followingstructural formula.

Membrane was made from the PI-BPDA-BAFL(4Et)-Br as in Example 1 and, asfor gas permeabilities, the membrane of the bromine-modified cardopolyimides showed somewhat lower permeability coefficients of carbondioxide and nitrogen but improved carbon dioxide/nitrogen separationfactor compared with PI-BPDA-BAFl(4Et):

EXAMPLE 31 Synthesis of PI-6FDA-BAAN(4Me)-Br

Using 9,9-bis(3′,5′-dimethyl-4′-aminophenyl)anthrone-10 [BAAN(4Me)] and6FDA in equimolar amounts, the polymerization was carried out inaccordance with a general condensation reaction such as shown in Example1 to give PI-6FDA-BAAN(4Me) represented by the following structuralformula.

Using the PI-6FDA-BAAN(4Me) and NBS, the reaction for modification bybromine, purification, and analysis were carried out as in Example 1.Several % of the 12 hydrogen atoms in the benzyl position was brominatedto give PI-6FDA-BAAN(4Me)-Br represented by the following structuralformula.

Membrane was made from the PI-6FDA-BAAN(4Me)-Br as in Example 1 and, asfor gas permeabilities, the membrane of the bromine-modified cardopolyimides showed somewhat lower permeability coefficients of carbondioxide and nitrogen but improved carbon dioxide/nitrogen separationfactor compared with PI-6FDA-BAAN(4Me).

EXAMPLE 32 Synthesis of PI-BPDA-BAMe(4Me)-Br

Using 1,1-bis(3′,5′-dimethyl-4′-aminophenyl)-4-methylcyclohexane[BAME(4Me)] and BPDA in equimolar amounts, the polymerization wascarried out in accordance with a general condensation reaction such asshown in Example 1 to give PI-BPDA-BAME(4Me) represented by thefollowing structural formula.

Using the PI-BPDA-BAME(4Me) and NBS, the reaction for modification bybromine, purification, and analysis were carried out as in Example 1.Several % of the 12 hydrogen atoms in the benzyl position was brominatedto give PI-BPDA-BAME(4Me)-Br represented by the following structuralformula.

Membrane was made from the PI-BPDA-BAME(4Me)-Br as in Example 1 and, asfor gas permeabilities, the membrane of the bromine-modified cardopolyimides showed somewhat lower permeability coefficients of carbondioxide and nitrogen but improved carbon dioxide/nitrogen separationfactor compared with PI-BPDA-BAME(4Me).

EXAMPLE 33 Synthesis of PA-BAFL(4Me)-Br

In a solvent such as dimethylacetamide (DMAc) was dissolved9,9-bis(3′,5′-dimethyl-4′-aminophenyl)fluorene [BAFL(4Me)] and,according to a general polymerization procedure for the preparation ofpolyamides, the solution was treated with an equimolar amount ofterephthaloyl dichloride at low temperature to give polyamidesPA-BAFL(4Me) represented by the following general formula.

Using the PA-BAFL(4Me) and NBS, the reaction for modification bybromine, purification, and analysis were carried out as in Example 1.Several % of the 12 hydrogen atoms in the benzyl position was brominatedto give PA-BAFL(4Me)-Br represented by the following structural formula.

Membrane was made from PA-BAFL(4Me)-Br as in Example 1 and, as for gaspermeabilities, the membrane of the bromine-modified cardo polyamidesshowed somewhat lower permeability coefficients of carbon dioxide andnitrogen but improved carbon dioxide/nitrogen separation factor comparedwith PA-BAFL(4Me).

EXAMPLE 34 Synthesis of PA-BAPI(4Me)-Br

Using 3,3-bis(3′,5′-dimethyl-4′-aminophenyl)phthalide [BAPI(4Me)] andisophthaloyl dichloride in equimolar amounts, the polymerizationreaction for the preparation of polyamides was carried out as in Example33 to give polyamides PA-BAPI(4Me) represented by the followingstructural formula.

Using the PA-BAPI(4Me) and NBS, the reaction for modification bybromine, purification, and analysis were carried out as in Example 1.Several % of the 12 hydrogen atoms in the benzyl position was brominatedto give PA-BAPI(4Me)-Br represented by the following structural formula.

Membrane was made from the PA-BAPI(4Me)-Br as in Example 1 and, as forgas permeabilities, the membrane of the bromine-modified cardopolyamides showed somewhat lower permeability coefficients of carbondioxide and nitrogen but improved carbon dioxide/nitrogen separationfactor compared with PA-BAPI(4Me).

EXAMPLE 35 Synthesis of PS-BHCH(4Me)-Br

Polyethersulfones PS-BHCH(4Me) represented by the following structuralformula were obtained by a synthetic method for preparingpolyethersulfones by an aromatic nucleophilic substitution reaction, forexample, by refluxing1,2-bis(3′,5′-dimethyl-4′-hydroxyphenyl)cyclohexane [BHCH(4Me)] togetherwith an equimolar amount of bis(4-chlorophenyl)sulfone and an amountslightly exceeding equimolar of potassium carbonate in dimethylacetamide(DMAc)-toluene, then removing the toluene under reduced pressure, andheating the mixture further at 160° C. for 10-12 hours.

Using the PS-BHCH(4Me) and NBS, the reaction for modification bybromine, purification, and analysis were carried out as in Example 1.Several % of the 12 hydrogen atoms in the benzyl position was brominatedto give PS-BHCH(4Me)-Br represented by the following structural formula.

Membrane was made from the PA-BHCH(4Me)-Br as in Example 1 and, as forgas permeabilities, the membrane of the bromine-modified cardopolyethersulfones showed somewhat lower permeability coefficients ofcarbon dioxide and nitrogen but improved carbon dioxide/nitrogenseparation factor compared with PS-BHCH(4Me).

EXAMPLE 36 Synthesis of PS-BHCHE-Br

Polyethersulfones PS-BHCHE represented by the following structuralformula were obtained by a synthetic method for preparingpolyethersulfones by an aromatic nucleophilic substitution reaction, forexample, by protecting the double bond of1,1-bis(4′-hydroxyphenyl)-3-cyclohexene [BHCHE], refluxing the protectedBHCHE together with an equimolar amount of bis(4-chlorophenyl)sulfoneand an amount slightly exceeding equimolar of potassium carbonate indimethylacetamide-toluene, then removing the toluene under reducedpressure, and heating the mixture further at 160° C. for 10-12 hours.

Using the PS-BHCHE and NBS, the reaction for modification by bromine,purification, and analysis were carried out as in Example 1. Several %of the 4 hydrogen atoms in the allyl position was brominated to givePS-BHCHE-Br represented by the following structural formula.

Membrane was made from the PS-BHCHE-Br as in Example 1 and, as for gaspermeabilities, the membrane of the bromine-modified cardopolyether-sulfones showed somewhat lower permeability coefficients ofcarbon dioxide and nitrogen but improved carbon dioxide/nitrogenseparation factor compared with PS-BHCHE.

EXAMPLE 37 Synthesis of PPO(2Me)-Br

Following a procedure for polymerization by oxidative coupling, oxygenwas passed through a solution of 2,6-dimethylphenol in nitrobenzene at25-50° C. in the presence of a copper chloride(I)-amine complex catalystto give PPO(2Me) represented by the following structural formula.

Using the PPO(2Me) and NBS, the reaction for modification by bromine,purification, and analysis were carried out as in Example 1. Several %of the 6 hydrogen atoms in the benzyl position was brominated to givePPO(2Me)-Br represented by the following structural formula.

Membrane was made from the PPO(2Me) as in Example 1 and, as for gaspermeabilities, the membrane of the bromine-modified poly(p-phenylene)showed somewhat lower permeability coefficients of carbon dioxide andnitrogen but improved carbon dioxide/nitrogen separation factor comparedwith PPO(2Me).

EXAMPLE 38 Synthesis of PI-BPDA-ODA(4Me)-Br

Using bis(3,5-dimethyl-4-aminophenyl)ether and BPDA in equimolaramounts, a general procedure for the condensation reaction for preparingpolyimides such as shown in Example 1 was followed to givePI-BPDA-ODA(4Me) represented by the following structural formula.

Using the PI-BPDA-ODA(4Me) thus obtained and NBS, the reaction formodification by bromine, purification, and analysis were carried out asin Example 1. Several % of the 12 hydrogen atoms in the benzyl positionwas brominated to give PI-BPDA-ODA(4Me)-Br represented by the followingstructural formula.

Membrane was made from the PI-BPDA-ODA(4Me)-Br as in Example 1 and, asfor gas permeabilities, the membrane of the bromine-modified polyimidesshowed somewhat lower permeability coefficients of carbon dioxide andnitrogen but improved carbon dioxide/nitrogen separation factor comparedwith PI-BPDA-ODA(4Me).

EXAMPLE 39 Synthesis of PI-BPDA-BNFL(2Me)-Br

Using 9,9-bis(methyl-4′-aminonaphthyl)fluorene [BNFL(2Me)] and BPDA inequimolar amounts, a general procedure for the condensation reaction forpreparing polyimides such as shown in Example 1 was followed to givePI-BPDA-BNFL(2Me) represented by the following structural formula.

Using the PI-BPDA-BNFL(2Me) thus obtained and NBS, the reaction formodification by bromine, purification, and analysis were carried out asin Example 1. Several % of the 6 hydrogen atoms in the benzyl positionwas brominated to give PI-BPDA-BNFL(2Me)-Br represented by the followingstructural formula.

Membrane was made from the PI-BPDA-BNFL(2Me)-Br as in Example 1 and, asfor gas permeabilities, the membrane of the bromine-modified cardopolyimides showed somewhat lower permeability coefficients of carbondioxide and nitrogen but improved carbon dioxide/nitrogen separationfactor compared with PI-BPDA-BNFL(2Me).

EXAMPLE 40 Synthesis of PI-BPDA-BAMFL(2Me)-Br

Using dimethylated 9,9-bis(1′-aminomethyl)fluorene [BAMFL(2Me)] and BPDAin equimolar amounts, a general procedure for the condensation reactionfor preparing polyimides such as shown in Example 1 was followed to givePI-BPDA-BAMFL(2Me) represented by the following structural formula.

Using the PI-BPDA-BAMFL(2Me) thus obtained and NBS, the reaction formodification by bromine, purification, and analysis were carried out asin Example 1. Several % of the 6 hydrogen atoms in the benzyl positionwas brominated to give PI-BPDA-BAMFL(2Me)-Br represented by thefollowing structural formula.

Membrane was made from the PI-BPDA-BAMFL(2Me)-Br as in Example 1 and, asfor gas permeabilities, the membrane of the bromine-modified cardopolyimides showed somewhat lower permeability coefficients of carbondioxide and nitrogen but improved carbon dioxide/nitrogen separationfactor compared with PI-BPDA-BAMFL(2Me).

EXAMPLE 41 Synthesis of PI-BPDA-BACHE-Br

Using 1,1-bis(4′-aminophenyl)-3-cyclohexene [BACHE] whose double bond isprotected and BPDA in equimolar amounts, a general procedure for thecondensation reaction for preparing polyimides such as shown in Example1 was followed and the resulting polymers were deprotected to givePI-BPDA-BACHE represented by the following structural formula.

Using the PI-BPDA-BACHE thus obtained and NBS, the reaction formodification by bromine, purification, and analysis were carried out asin Example 1. Several % of the 4 hydrogen atoms in the allyl positionwas brominated to give PI-BPDA-BACHE-Br represented by the followingstructural formula.

Membrane was made from the PI-BPDA-BACHE-Br as in Example 1 and, as forgas permeabilities, the membrane of the bromine-modified cardopolyimides showed somewhat lower permeability coefficients of carbondioxide and nitrogen but improved carbon dioxide/nitrogen separationfactor compared with PI-BPDA-BACHE.

EXAMPLE 42 Synthesis of PA-BAPI(4Me)-Br

The PI-BPDA-BACHE-Br prepared in Example 41 was dissolved intetrahydrofuran (THF) and treated with four times in mole oftetrabutylammonium isothiocyanate to effect partial replacement of thebromine atoms in the allyl position by isothiocyanato groups and giveisothiocyanato-modified cardo polyimides represented by the followingstructural formula.

EXAMPLE 43 Synthesis of Bromine-modified Natural Rubber

Using natural rubber (polyisoprene) represented by the followingstructural formula,

the reaction for modification by bromine, purification, and analysiswere carried out as in Example 1. Several % of the 7 hydrogen atoms inthe allyl position was brominated to give bromine-modified naturalrubber represented by the following structural formula.

EXAMPLE 44 Synthesis of PFL(2Me)-Br

Dimethylated methylidenefluorene [FL(2Me)] was subjected to additionpolymerization to give polymethylidenefluorene [PFL(2Me)] represented bythe following structural formula.

Using the PFL(2Me) thus obtained and NBS, the reaction for modificationby bromine, purification, and analysis were carried out as in Example 1.Several % of the 6 hydrogen atoms in the benzyl position was brominatedto give PFL(2Me)-Br represented by the following structural formula.

Membrane was made from the PFL(2Me)-Br as in Example 1 and, as for gaspermeabilities, the membrane of the bromine-modifiedpolymethylidene-fluorene showed somewhat lower permeability coefficientsof carbon dioxide and nitrogen but improved carbon dioxide/nitrogenseparation factor compared with PFL(2Me).

EXAMPLE 45 Synthesis of PPHTL(Me)-Br

Methylated methylidenephthalide [PHTL(Me)] was subjected to additionpolymerization to give polymethylidenephthalide [PPHTL(Me)] representedby the following formula.

Using the PPHTL(Me) thus obtained and NBS, the reaction for modificationby bromine, purification, and analysis were carried out as in Example 1.Several % of the 3 hydrogen atoms in the benzyl position was brominatedto give PPHTL(Me)-Br represented by the following structural formula.

Membrane was made from the PPHTL(Me)-Br as in Example 1 and, as for gaspermeabilities, the membrane of the bromine-modified cardo polyimidesmodified polymethylidene-phthalide showed somewhat lower permeabilitycoefficients of carbon dioxide and nitrogen but improved carbondioxide/nitrogen separation factor compared with PPHTL(Me).

EXAMPLE 46 Synthesis of PA-BAMFL(2Me)-Br

Using dimethylated 9,9-bis(1′-aminomethyl)fluorene [BAMFL(2Me)] andterephthaloyl dichloride in equimolar amounts, a general procedure forpreparing polyimides as shown in Example 33 was followed to givePA-BAMFL(2Me) represented by the following structural formula.

Using the PA-BAMFL(2Me) thus obtained and NBS, the reaction formodification by bromine, purification, and analysis were carried out asin Example 1. Several % of the 6 hydrogen atoms in the benzyl positionwas brominated to give PA-BAMFL(2Me)-Br represented by the followingstructural formula.

Membrane was from the PA-BAMFL(2Me)-Br as in Example 1 and, as for gaspermeabilities, the membrane of the bromine-modified cardo polyimidesshowed somewhat lower permeability coefficients of carbon dioxide andnitrogen but improved carbon dioxide/nitrogen separation factor comparedwith PA-BAMFL(2Me).

EXAMPLE 47 Preparation and Performance of Asymmetric Hollow FiberMembrane

Asymmetric hollow-fiber membranes were made continuously from thePI-PMBP64-BAFL(4Me)-Br(29.0%) prepared in Example 7 in an apparatus formaking hollow-fiber membranes equipped with a double-ring spinneret. Asolution of the PI-PMBP64-BAFL(4Me)-Br(29.0%) in N-methylpyrrolidone(NMP) was forced through the outer annular orifice of the double-ringspinneret and, at the same time, deionized water as a bore liquid wasforced through the inner circular orifice; the two jets were guided intoa solvent-removing vessel filled with deionized water to form asymmetrichollow-fiber membranes having an acitve layer for gas separation insidethe hollow fiber. The hollow-fiber membranes were stripped of theremaining solution in deionized water, dried, heated at approximately300° C. for 30 minutes, bundled, and packed in a housing to prepare amodule.

The module of asymmetric hollow-fiber membranes was tested for the rateof permeation of gases at 35° C. (308 K) and at a pressure difference of1 atmosphere (1.0×10⁵ Pa) in a reduced presssure type instrument formeasuring the rare of permeation of gases equipped with a gaschromatograph as a detector. The results were as follows.

[Rate of permeation of carbon dioxide]

38×10⁻¹⁶m³/(m².s.Pa)

[5.0×10⁻⁴cm³(STP)/(cm².s.cmHg)]

[Rate of permeation of nitrogen]

1.1×10⁻¹⁶m³/(m².s.Pa)

[0.14×10⁻⁴cm³(STP)/(cm².s.cmHg)]

[Carbon dioxide/nitrogen separation factor] 35

Comparative Example 1

In 50 ml of NMP was dissolved 5 g of the PI-BPDA-BAFL(4Me) prepared inExample 1 by heating at 80° C. and the solution was cast on a glassplate in a uniform thickness and dried in a dryer at 60° C. for 1 hourand at 80° C. for 5 hours. Thereafter, the dried glass plate wasimmersed in distilled water and the film was peeled off the glass plateand dried in a vacuum dryer at 210° C. for 12 hours. Thus the cardopolyimides PI-BPDA-BAFL(4Me) were made into membrane.

Gas permeabilities of the cardo polyimide membrane thus made were asfollows.

[Permeability coefficient of nitrogen]

171×10⁻¹⁸m³.m/(m².s.Pa) (22.8 barrer)

[Carbon dioxide/nitrogen separation factor] 22

Comparative Example 2

The cardo polyimides PI-6FDA-BAFL(4Me) prepared in Example 4 were madeinto membrane as in Comparative Example 1.

Gas permeabilities of the cardo polyimide membrane thus made were asfollows.

[Permeability coefficient of carbon dioxide]

6470×10⁻¹⁸m³.m/(m².s.Pa) (862 barrer)

[Permeability coefficient of nitrogen]

326×10⁻¹⁸m³.m/(m².s.Pa) (43.5 barrer)

[Carbon dioxide/nitrogen separation factor] 20

Comparative Example 3

The cardo polyimides PI-PMBP64-BAFL(4Me) prepared in Example 7 were madeinto membrane as in Comparative Example 1.

Gas permeabilities of the cardo polyimide membrane thus made were asfollows.

[Permeability coefficient of carbon dioxide]

7800×10⁻¹⁸m³.m/(m².s.Pa) (1040 barrer)

[Permeability coefficient of nitrogen]

339×10⁻¹⁸m³.m/(m².s.Pa) (45.2 barrer)

[Carbon dioxide/nitrogen separation factor] 23

Comparative Example 4

The cardo polyimides PI-BTDA-BAFL(4Me) prepared in Example 22 were madeinto membrane as in Comparative Example 1.

Gas permeabilities of the cardo polyimide membrane thus made were asfollows.

[Permeability coefficient of carbon dioxide]

2240×10⁻¹⁸m³.m/(m².s.Pa) (298 barrer)

[Permeability coefficient of nitrogen]

74×10⁻¹⁸m³.m/(m².s.Pa) (9.9 barrer)

[Carbon dioxide/nitrogen separation factor] 30

[Relationship Between the Amount of NBS Used and the Degree ofModification by Bromine]

In respect to the bromination reactions with the use of NBS in theaforementioned Examples 1 to 10 and 22 to 26, the relationship betweenthe amount of NBS used and the rate of modification by bromine isillustrated in FIG. 3 in terms of the relationship between the molarratio of NBS in use to the hydrogen atoms in the four methyl groupsrepresented by R₁₂, R₁₄, R₁₇, and R₁₉ in the structural formula (A) inthe general formula (1) (or 12 hydrogen atoms in the benzyl positions)or the molar ratio (NBS/12H) and the rate of modification by bromine.

The results shown in FIG. 3 clearly prove that the bromination ofhydrogen atoms in the benzyl position in cardo polyimides can becontrolled easily by the amount of the brominating agent NBS in use.

[Relationship Between the Rate of Modification by Bromine and the CO₂/N₂Separation Factor (α)]

The relationship between the rate of modification by bromine and theCO₂/N₂ separation factor is shown in FIG. 4 for Examples 7 to 10 andComparative Example 3.

The results shown in FIG. 4 indicate that the CO₂/N₂ separation factorimproves as the rate of modification by bromine increases and the gasseparation factor (α) can be controlled well by controlling the rate ofmodification by bromine in the case of the membranes of bromine-modifiedcardo polyimides represented by the general formula (1).

{Relationship Between the Rate of Modification by Bromine and the GasPermeability [P(CO₂)]}

The relationship between the rate of modification by bromine and the gaspermeability [P(CO₂)] is shown in FIG. 5 for Examples 7 to 10 andComparative Example 3.

The results shown in FIG. 5 indicate that the gas permeability [P(CO₂)]diminishes as the rate of modification by bromine increases and the gaspermeability can be controlled well by controlling the rate ofmodification by bromine in the case of the membranes of bromine-modifiedcardo polyimides represented by the general formula (1).

The results shown above in FIGS. 3 to 5 indicate that, withbromine-modified cardo polyimide membranes of this invention, the amountof NBS to be used as a brominating agent controls the rate ofmodification by bromine in the bromination reaction and, in turn, therate of modification by bromine controls the gas selectivity (α) and gaspermeability [P(CO₂)], indicators of the performance of gas separationmembranes, and gas separation membranes of desired separationperformance can be designed with ease.

INDUSTRIAL APPLICABILITY

This invention provides gas separation membranes of modified cardopolyimides which exhibit excellent, controllable, easy-to-designperformance in gas permeability and gas selectivity.

This invention also provides modified cardo polyimides from which gasseparation membranes exhibiting excellent and easy-to-design performancein gas permeability and gas selectivity can be produced and a processfor producing said cardo polyimides.

What is claimed is:
 1. A gas separation material, comprising: a resinmaterial for gas separation base comprising polymer of a cardo structurein which hydrogen atoms in a side-chain benzyl and/or allyl position arehalogenated at a rate of modification by halogen of 0.1% or more. 2.Resin material for gas separation base as described in claim 1, whereinsaid polymer is polyimide.
 3. Resin material for gas separation base asdescribed in claim 1, wherein said polymer is polyimide of a cardostructure represented by the following general formula (1)

wherein X is a divalent residue of an organic group and at least partlya divalent residue of an organic group represented by the followingstructural formula (A)

and Y is a tetravalent residue of an organic group; in the structuralformula (A), at least one of R₁ to R₂₀ is a halogen-modified substituentrepresented by —CZR₂₁R₂₂ (wherein Z is a halogen atom and R₂₁ and R₂₂will be defined later), the remainder of R₁ to R₂₀ and R₂₁ and R₂₂ inthe halogen-modified substituent are hydrogen, halogen, linear orbranched or cyclic unsubstituted or substituted alkyl, alkenyl, alkynyl,or aryl group; the aforementioned alkyl, alkenyl, alkynyl, and arylgroups may contain one kind or two kinds or more of hetero atomsselected from nitrogen, oxygen, sulfur, phosphorus and halogens and maybe identical with or different from one another, the aforementionedremainder of R₁ to R₂₀ and R₂₁ and R₂₂ may pair and join togetherdirectly or through another atom to form a saturated or unsaturated bondin a cyclic structure, any one of R₁₁ to R₁₅ and any one of R₁₆ to R₂₀are respectively bonded to the nitrogen atom in the imide skeleton, andany one of R₁ to R₅ and any one of R₆ to R₁₀ join together directly orthrough another atom to form a saturated or unsaturated bond in a cyclicstructure.
 4. Resin material for gas separation base as described inclaim 3, wherein the structural formula (A) in the general formula (1)is a divalent residue of an organic group containing a fluorene skeletonrepresented by the following structural formula (B)

wherein R₁ to R₄ and R₇ to R₂₀ are as defined in the case of thestructural formula (A).
 5. Resin material for gas separation base asdescribed in claim 4, wherein at least one substituent selected from R₁₁to R₂₀ is a halogen-modified substituent.
 6. Resin material for gasseparation base as described in any one of claims 1 to 5, wherein therate of modification by halogen of the hydrogen atoms in the side-chainbenzyl and/or allyl position is 20% or more.
 7. Resin material for gasseparation base comprising polyimide of a cardo-type structurerepresented by the following general formula (1)

wherein X is a divalent residue of an organic group and at least partlya divalent residue of an organic group represented by the followingstructural formula (A)

and Y is a tetravalent residue of an organic group; in the structuralformula (A), at least one of R₁ to R₂₀ is a functional group-modifiedsubstituent represented by —CFuZR₂₁R₂₂, —CFu₂R₂₁ and/or —CFu₃ (whereinFu is a functional group or a derivative thereof which can be introducedby replacing a halogen atom in the benzyl and/or allyl position), theremainder of R₁ to R₂₀ and R₂₁ and R₂₂ are hydrogen, halogen, linear orbranched or cyclic unsubstituted or substituted alkyl, alkenyl, alkynyl,or aryl group; the aforementioned alkyl, alkenyl, alkynyl, and arylgroups may contain one kind or two kinds or more of hetero atomsselected from nitrogen, oxygen, sulfur, phosphorus and halogens and maybe identical with or different from one another, the aforementionedremainder of R₁ to R₂₀ and R₂₁ and R₂₂ may pair and join togetherdirectly or through another atom to form a saturated or unsaturated bondin a cyclic structure, any one of R₁₁ to R₁₅ and any one of R₁₆ to R₂₀are respectively bonded to the nitrogen atom in the imide skeleton, andany one of R₁ to R₅ and any one of R₆ to R₁₀ join together directly orthrough another atom to form a saturated or unsaturated bond in a cyclicstructure.
 8. Resin material for gas separation base as described inclaim 7, wherein the structural formula (A) in the general formula (1)is a divalent residue of an organic group containing a fluorene skeletonrepresented by the following structural formula (B)

wherein R₁ to R₄ and R₇ to R₂₀ are as defined in the case of thestructural formula (A).
 9. Resin material for gas separation base asdescribed in claim 8, wherein at least one substituent selected from R₁₁to R₂₀ is a functional group-modified substituent.
 10. Resin materialfor gas separation base comprising polymer in which the hydrogen atomsin the side-chain benzyl and/or allyl position are halogenated at a rateof modification by halogen of 34% or more.
 11. Resin material for gasseparation base as described in claim 10, wherein said polymer ispolyimide.
 12. Polymer containing a structure of cardo polyimiderepresented by the following general formula (1)

wherein X is a divalent residue of an organic group and at least partlya divalent residue of an organic group represented by the followingstructural formula (A)

and Y is a tetravalent residue of an organic group; in the structuralformula (A), at least one of R₁ to R₂₀ is a halogen-modified substituentrepresented by —CZR₂₁R₂₂ (wherein Z is a halogen atom and R₂₁ and R₂₂will be defined later), the remainder of R₁ to R₂₀ and R₂₁ and R₂₂ inthe halogen-modified substituent are hydrogen, halogen, linear orbranched or cyclic unsubstituted or substituted alkyl, alkenyl, alkynyl,or aryl group; the aforementioned alkyl, alkenyl, alkynyl, and arylgroups may contain one kind or two kinds or more of hetero atomsselected from nitrogen, oxygen, sulfur, phosphorus and halogens and maybe identical with or different from one another, the aforementionedremainder of R₁ to R₂₀ and R₂₁ and R₂₂ may pair and join togetherdirectly or through another atom to form a saturated or unsaturated bondin a cyclic structure, any one of R₁₁ to R₁₅ and any one of R₁₆ to R₂₀are respectively bonded to the nitrogen atom in the imide skeleton, andany one of R₁ to R₅ and any one of R₆ to R₁₀ join together directly orthrough another atom to form a saturated or unsaturated bond in a cyclicstructure.
 13. Polymer as described in claim 12, wherein the structuralformula (A) in the general formula (1) is a divalent residue of anorganic group containing a fluorene skeleton represented by thefollowing structural formula (B)

wherein R₁ to R₄ and R₇ to R₂₀ are as defined earlier.
 14. Polymer asdescribed in claim 13, wherein at least one substituent selected fromR₁₁ to R₂₀ is a halogen-modified substituent.
 15. Polymer as describedin any one of claims 12 to 14, wherein the rate of modification byhalogen in the side-chain benzyl and/or allyl position is 20% or more.16. Polymer containing a structure of cardo polyimide represented by thefollowing general formula (1)

wherein X is a divalent residue of an organic group and at least partlya divalent residue of an organic group represented by the followingstructural formula (A)

and Y is a tetravalent residue of an organic group; in the structuralformula (A), at least one of R₁ to R₂₀ is a functional group-modifiedsubstituent represented by —CFuZR₂₁R₂₂, —CFu₂R₂₁ and/or —CFu₃ (whereinFu is a functional group or a derivative thereof which can be introducedby replacing a halogen atom in the benzyl and/or allyl position), theremainder of R₁ to R₂₀ and R₂₁ and R₂₂ are hydrogen, halogen, linear orbranched or cyclic unsubstituted or substituted alkyl, alkenyl, alkynyl,or aryl group; the aforementioned alkyl, alkenyl, alkynyl, and arylgroups may contain one kind or two kinds or more of hetero atomsselected from nitrogen, oxygen, sulfur, phosphorus and halogens and maybe identical with or different from one another, the aforementionedremainder of R₁ to R₂₀ and R₂₁ and R₂₂ may pair and join togetherdirectly or through another atom to form a saturated or unsaturated bondin a cyclic structure, any one of R₁₁ to R₁₅ and any one of R₁₆ to R₂₀are respectively bonded to the nitrogen atom in the imide skeleton; andany one of R₁ to R₅ and any one of R₆ to R₁₀ join together to form asaturated or unsaturated bond in a cyclic structure.
 17. Polymer asdescribed in claim 16, wherein the structural formula (A) in the generalformula (1) is a divalent residue of an organic group containing afluorene skeleton represented by the following structural formula (B)

wherein R₁ to R₄ and R₇ to R₂₀ are as defined earlier.
 18. Polymer asdescribed in claim 17, wherein at least one substituent selected fromR₁₁ to R₂₀ is a functional group-modified substituent.
 19. A process forproducing polymer containing a structure of halogen-modified cardopolyimide from a polymer containing a structure of cardo polyimiderepresented by the following general formula (1)

wherein X is a divalent residue of an organic group and at least partlya divalent residue of an organic group represented by the followingstructural formula (A)

and Y is a tetravalent residue of an organic group; in the structuralformula (A), at least one of R₁ to R₂₀ is a pre-modification substituentrepresented by —CHR₂₁R₂₂ (wherein R₂₁ and R₂₂ are as defined later), theremainder of R₁ to R₂₀ and R₂₁ and R₂₂ are hydrogen, halogen, linear orbranched or cyclic unsubstituted or substituted alkyl, alkenyl, alkynyl,or aryl group; the aforementioned alkyl, alkenyl, alkynyl, and arylgroups may contain one kind or two kinds or more of hetero atomsselected from nitrogen, oxygen, sulfur, phosphorus and halogens and maybe identical with or different from one another, the aforementionedremainder of R₁ to R₂₀ and R₂₁ and R₂₂ may pair and join togetherdirectly or through another atom to form a saturated or unsaturated bondin a cyclic structure, any one of R₁₁ to R₁₅ and any one of R₁₆ to R₂₀are respectively bonded to the nitrogen atom in the imide skeleton, andany one of R₁ to R₅ and any one of R₆ to R₁₀ join together directly orthrough another atom to form a saturated or unsaturated bond in a cyclicstructure; said process comprises treating said polymer containing astructure of cardo polyimide with a halogenating agent in moleequivalent corresponding to 0.01 to 3 times that of the hydrogen atomsin the benzyl and/or allyl position in said pre-modification substituentand effecting the reaction at a rate of modification by halogen of 0.1%or more to give said polymer containing a structure of halogen-modifiedcardo polyimide whose halogen-modified substituent is represented by—CZR₂₁R₂₂ (wherein Z is a halogen atom and R₂₁ and R₂₂ are as definedearlier).
 20. A process for producing polymer as described in claim 19,wherein the structural formula (A) in the general formula (1) contains afluorene skeleton represented by the following structural formula (B)

wherein R₁ to R₄ and R₇ to R₂₀ are as defined earlier.
 21. A process forproducing polymer as described in claim 20, wherein at least onesubstituent selected from R₁₁ to R₂₀ is a halogen-modified substituent.22. A process for producing polymer as described in any one of claims 19to 21, wherein the rate of modification by halogen of the hydrogen atomsin the side-chain benzyl and/or allyl position is 20% or more.
 23. Aprocess for producing polymer containing a functional group-modifiedsubstituent from a polymer containing a structure of cardo polyimiderepresented by the following general formula (1)

wherein X is a divalent residue of an organic group and at least partlya divalent residue of an organic group represented by the followingstructural formula (A)

and Y is a tetravalent residue of an organic group; in the structuralformula (A), at least one of R₁ to R₂₀ is a pre-modification substituentrepresented by —CHR₂₁R₂₂ (wherein R₂₁ and R₂₂ are as defined later), theremainder of R₁ to R₂₀ and R₂₁ and R₂₂ in the pre-modificationsubstituent are hydrogen, halogen, linear or branched or cyclicunsubstituted or substituted alkyl, alkenyl, alkynyl, or aryl group; theaforementioned alkyl, alkenyl, alkynyl, and aryl groups may contain onekind or two kinds or more of hetero atoms selected from nitrogen,oxygen, sulfur, phosphorus and halogens and may be identical with ordifferent from one another, the aforementioned remainder of R₁ to R₂₀and R₂₁ and R₂₂ may pair and join together directly or through anotheratom to form a saturated or unsaturated bond in a cyclic structure, anyone of R₁₁ to R₁₅ and any one of R₁₆ to R₂₀ are respectively bonded tothe nitrogen atom in the imide skeleton, and any one of R₁ to R₅ and anyone of R₆ to R₁₀ join together directly or through another atom to forma saturated or unsaturated bond in a cyclic structure; said processcomprises treating said polymer containing a structure of cardopolyimide with a halogenating agent in mole equivalent corresponding to0.01 to 3 times that of the hydrogen atoms in the benzyl and/or allylposition in said pre-modification substituent, effecting the reaction ata rate of modification by halogen of 0.1% or more to give polymercontaining a structure of halogen-modified cardo polyimide whosehalogen-modified substituent is represented by —CZR₂₁R₂₂ (wherein Z is ahalogen atom and R₂₁ and R₂₂ are as defined earlier), and treating theresulting polymer with a nucleophilic reagent containing a functionalgroup capable of undergoing substitution with the halogen atom in thehalogen-modified substituent thereby converting at least a part of saidhalogen-modified substituent to a functional group-modified substituentrepresented by —CFuR₂₁R₂₂, —CFu₂R₂₁ and/or —CFu₃ (wherein Fu is afunctional group or a derivative thereof which can be introduced byreplacing a halogen atom in the benzyl and/or allyl position).
 24. Resinmaterial for gas separation membrane as described in claim 1 in the formof gas separation membrane.
 25. Cardo polymer in which hydrogen atoms ina side-chain benzyl and/or allyl position are halogenated at a rate ofmodification by halogen of 0.1% or more.
 26. Cardo polymer as describedin claim 25, wherein said polymer is polyimide.
 27. Polymer containingcardo polymer modified by functional groups at least one of which isrepresented by —CFuR₂₁R₂₂, —CFu₂R₂₁ and/or —CFu₃ wherein Fu is afunctional group or a derivative thereof which can be introduced byreplacing a halogen atom in a side chain benzyl and/or allyl positionand R₂₁ and R₂₂ are hydrogen, halogen, linear or branched or cyclicunsubstituted or substituted alkyl, alkenyl, alkynyl or aryl group, maycontain one kind or two kinds or more of hetero atoms selected fromnitrogen, oxygen, sulfur, phosphorus and halogens, may be identical withor different from one another, and may join together or to other carbonatoms to form a saturated or unsaturated bond in cyclic structure. 28.Polymer as described in claim 27, wherein said polymer is polyimide. 29.Polymer as described in claim 27 useful for resin material for gasseparation base.
 30. Polymer as described in claim 28 useful for resinmaterial for gas separation base.
 31. Resin material for gas separationbase as described in claim 29 or 30 in the form of gas separationmembrane.